water therapy

What is water therapy

Water therapy is also called hydrotherapy, aquatic therapy, pool therapy or balneotherapy, is the external or internal use of water in any of its forms (water, ice, steam) for health promotion or treatment of various diseases with various temperatures, pressure, duration, and site 1). Water therapy is one of the naturopathic treatment modality used widely in ancient cultures including India, Egypt, China, etc. 2). Use of water in various forms and in various temperatures can produce different effects on different system of the body. Though many countries used water to produce different physiological/therapeutic effects on different part of the system for maintaining health, preventing, and treating the diseases, the scientific evidence-based effects are not well documented.

Water therapy in general

Superficial cold application may cause physiologic reactions such as decrease in local metabolic function, local edema, nerve conduction velocity, muscle spasm, and increase in local anesthetic effects 3). One hour head-out water immersions in various temperatures (57.2 °F [14°C], 68 °F [20°C] and 89.6 °F [32°C]) produced various effects.

Immersion at 89.6 °F [32°C] did not change metabolic rate and rectal temperature, but it lowered the heart rate (HR) by 15%, systolic blood pressure (SBP) and diastolic blood pressure (DBP) by 11% and 12%, respectively, compared, with controls at ambient air temperature 4). Along with heart rate and blood pressure (BP), the plasma renin activity, plasma cortisol, and aldosterone concentrations were also lowered by 46%, 34%, and 17%, respectively, while diuresis was increased by 107% 5).

Head-out water immersions at 68 °F [20°C] produced similar decrease in plasma renin activity, heart rate, systolic blood pressure, and diastolic blood pressure, in spite of lowered rectal temperature and increased metabolic rate by 93% 6). Plasma cortisol concentrations tended to decrease, while plasma aldosterone concentration was unchanged. Diuresis was increased by 89%. No significant differences in changes in plasma renin activity, aldosterone concentration, and diuresis compared with subjects immersed in 89.6 °F [32°C] 7).

Head-out water immersions at 57.2 °F [14°C] lowered rectal temperature and increased metabolic rate by 350%, heart rate, systolic blood pressure, and diastolic blood pressure by 5%, 7%, and 8%, respectively 8). Plasma noradrenaline and dopamine concentrations were increased by 530% and by 250%, respectively, while diuresis increased by 163%, which was more than at 89.6 °F [32°C]. Plasma aldosterone concentrations increased by 23%. Plasma renin activity was reduced. Cortisol concentrations tended to decrease. Plasma adrenaline concentrations remained unchanged. Changes in plasma renin activity were not related to changes in aldosterone concentrations 9).

Head-out water immersions therapy in different temperatures did not increase blood concentrations of cortisol 10). There was no correlation between changes in rectal temperature and changes in hormone production. The physiological changes induced by head-out water immersions are mediated by humoral control mechanisms, while responses induced by cold are mainly due to increased activity of the sympathetic nervous system 11).

Regular winter swimming significantly decreased tension, fatigue, memory, and mood negative state points with the duration of swimming period; significantly increased vigor-activity scores; relieved pain who suffered from rheumatism, fibromyalgia, or asthma; and improved general well-being in swimmers 12).

Water therapy benefits

The benefits of water therapy include enhanced aerobic capacity, improved muscle strength and endurance, increased joint range of motion (anti-spasticity), as well as decreased muscle fatigue and joint pain, enhanced cardiorespiratory functioning and a reduced cardiometabolic risk profile 13). Hot spring hydro-pressure therapy plays a crucial role in the recovery of burn patients 14) by contributing to the superficial improvement of the affected skin as well as by fostering a general sense of personal well-being. By targeting both the restoration of the skin’s physical properties and the strengthening of the patient’s psyche, their body’s ability to heal is increased. In France, hot spring water and hydro-pressure therapy are accepted as an important part of burn therapy with 2 annual sessions eligible for reimbursement through social insurance. Water physical therapy aids in reducing patients with spinal cord injury muscle spasticity and cardiometabolic risk profiles, while favourably enhancing underwater gait kinematics and cardiorespiratory capacity 15). However, more randomised control trials should be undertaken to increase the present body of knowledge.

Cardiovascular system

Cold exposure to small surface area produced compensatory vasodilatation in deeper vascular system resulting increased blood flow to the tissues underlying the site of exposure. This vascular reaction occurs mainly to maintain constant deep tissue temperature 16).

In patient with chronic heart failure, thermal vasodilatation following warm-water bathing and low-temperature sauna bathing at 140 °F (60°C) for 15 min improves cardiac function 17); repeated sauna-therapy (sauna-therapy) increased left ventricular ejection fraction; increased 6-min walk distance in association with improvement in flow-mediated dilation and increase in number of circulating CD34 (+) cells; reduced plasma levels of norepinephrine and brain natriuretic peptide. These indicates that sauna-therapy improves exercise tolerance in association with improvement in endothelial function 18). Low-temperature sauna bathing improves peripheral circulation in cerebral palsy (CP) 19).

After sauna-therapy reduced level of total and low density lipoprotein (LDL) “bad: cholesterol concentration, while increased level of high density lipoprotein (HDL) “good” cholesterol was observed. These changes are good prognoses for the prevention of ischemic heart disease 20). Sauna-therapy increases endothelial nitric oxide synthase (eNOS) activity and improves cardiac function in heart failure and improve peripheral blood flow in ischemic limbs. In myocardial infarction (heart attack)-induced Wistar rats sauna-therapy increases myocardial endothelial nitric oxide synthase (eNOS), vascular endothelial growth factor mRNA levels. It attenuates cardiac remodeling after heart attack through improving coronary vascularity in the noninfarcted myocardium and thus sauna-therapy might serve as a novel noninvasive therapy for patients with heart attack 21). Acute heart attack was thought to result from thrombosis or plaque rupture because of coronary artery spasm. The vasospasm might be induced by stimulation of the alpha-adrenergic receptors during alternating heat exposure during sauna bath followed by rapid cooling during cold water bath. This effect showed the dangers of rapid cooling after sauna bathing in patients with coronary risk factors 22). Regular sauna-therapy (either radiant heat or far-infrared units) appears to be safe and produce multiple health benefits but use of sauna-therapy in early pregnancy is a potential concern because evidence suggesting that hyperthermia might be teratogenic 23).

Cold water immersion (head-out cold water immersions) induces significant physiological and biochemical changes in the body such as increase in heart rate, BP, metabolism, and peripheral catecholamine concentration; and decrease in cerebral blood flow 24).

Reduction in heart rate, and increases in systolic and diastolic biventricular functions, were observed during acute warm-head-out water immersions 25). In contrast, increase in heart rate and a decrease in systolic blood pressure and diastolic blood pressure were observed in 30 min of head-out head-out water immersions (38.41 ± 0.04°C) 26).

Hyperthermic immersion produced shortening of activated partial thromboplastin time. During hyperthermic immersion, plasminogen activator inhibitor activity was decreased; thrombocyte count was increased; increases in tissue-type plasminogen activator concentration and leukocytes count were attributed to hemoconcentration. Immediately after hyperthermic immersion, fibrinogen concentration decreased but increased during recovery. During thermo-neutral immersion prothrombin time, plasminogen activator inhibitor activity and granulocyte count ecreased. Warm water bathing leads to hemoconcentration and minimal activation of coagulation; decrease in plasminogen activator inhibitor-1 activity. During warm water bathing, marked risk for thrombotic or bleeding complications in healthy males could not be ascertained 27). During contrast baths, longer duration in the second heating phase was required to produce sufficient fluctuation in blood flow 28).

Head-out water immersions up-to shoulder levels at different temperatures (77 °F [25°C], 93.2 °F [34°C], and 104 °F [40°C]) showed no significant effect on cardiac output in 77 °F [25°C] compared with 93.2 °F [34°C], but in 104 °F [40°C] a considerable increase in cardiac output was observed 29).

Carbon dioxide (CO2) enriched head-out water immersions reduced free radical plasma levels, raised antioxidants levels, and induce peripheral vasodilatation suggests improvement in microcirculation 30). Decrease in tympanic temperature; increase in cutaneous blood flow at immersed site was significantly greater in CO2-head-out water immersions compared with fresh head-out water immersions 31). The three main effects of CO2 enriched head-out water immersions are decline in core temperature, increase in cutaneous blood flow, and elevation of score on thermal sensation, which were analyzed 32).

Respiratory system

head-out water immersions up-to shoulder levels at different temperatures (77 °F [25°C], 93.2 °F [34°C], and 104 °F [40°C]) showed increased metabolic rate, oxygen (O2) consumption (VO2) only at 77 °F [25°C]. Two main factors affecting O2 transport during immersion are temperature and hydrostatic pressure. O2 transport was improved above neutral temperature, because of increase in cardiac output resulting from the combined actions of hydrostatic counter pressure and body heating. Below neutral temperature, O2 transport is altered. At any of the temperatures tested, the pulmonary tissue volume and arterial blood gases were not significantly affected 33).

Significant decrease in vital capacity (VC) with bath temperature was observed (i.e., vital capacity at 40°C >34°C >25°C). Significant increase in tidal volume (VT) in cold or hot water compared with thermo neutral water (i.e., tidal volume 40°C >34°C< 25°C). Alterations in respiratory muscles functioning might produce variations of the pulmonary volumes as a function of water temperature 34).

Cold water immersions was associated with increase in respiratory minute volume and decrease in end tidal CO2 partial pressure 35). Repeated cold water stimulations reduced frequency of infections; increased peak expiratory flow, lymphocyte counts, and expression of gamma-interferon; modulated interleukin expression; and improved quality of life (quality of life) in patients with chronic obstructive pulmonary disease 36).

In children suffering from recurrent and asthmatic bronchitis in remission, a single total air bath, or douche and local (cooling of the feet with water) exposure to mild cold did not raise noticeable disorders of the respiratory function. Local cold procedures improve bronchial patency but heat exposure resulted in its worsening 37).

Inhaling hot air while in a sauna produced no significant impact on overall symptom severity of common cold 38). A male track and field athlete, a case of breathing difficulties at rest and during exercise, was exacerbated in the supine position and during head-out water immersions 39).

Nervous system

Three cold modalities such as ice massage, ice pack, and cold water immersions applied to right calf region for 15 minutes reduced skin temperature (mean 64.76 °F [18.2°C]); reduced amplitude and increased latency and duration of compound action potential. It also reduced sensory nerve conduction velocity by 20.4, 16.7, and 22.6 m/s and motor nerve conduction velocity by 2.5, 2.1, and 8.3 m/s, respectively. Even though all three modalities effectively reduced skin temperature and sensory conduction at a physiological level, cold water immersions is the most indicated, effective modality for inducing therapeutic effects associated with the reduction of motor nerve conduction 40).

Temperature and pressure of water in aquatic or hydrotherapy can block nociceptors by acting on thermal receptors and mechanoreceptors and exert positive effect on spinal segmental mechanisms, which is useful for painful condition 41). Forty sessions of Ai Chi aquatic exercise program improves pain, spasms, disability, fatigue, depression, and autonomy in patient with multiple sclerosis 42).

In a study on physiotherapy on land or water in patient with Parkinson’s disease (Parkinson’s disease), functional reach test was improved in both therapies, but Berg Balance Scale (BBS) and Unified Parkinson’s Disease Rating Scale were improved only in aquatic therapy group. It indicates improvement in postural stability in Parkinson’s disease was significantly larger after aquatic therapy 43).

Sauna bath on paraplegic (P) group and tetraplegic (T) group, heart rate increased significantly during sauna but decreased significantly during postsauna phase in paraplegic group. diastolic blood pressure significantly reduced in tetraplegic group during postsauna phase but no significant changes in systolic blood pressure in both the groups.

In a study on cerebral palsy, low-temperature sauna bathing produced increase in heart rate and cardiac output; decrease in BP and total peripheral resistance; significant improvement in skin blood flow, blood flow velocity, pulsatile index, and resistive index; decrease in numbness and chronic myalgia of the extremities with no adverse effects 44).

Ten minutes of immersions in whirlpools produced increases in pulse and finger temperature with increased feelings of well-being and decreased state anxiety 45). CO2-head-out water immersions activates parasympathetic nerve activity in humans 46).

Adapted cold shower might have antipsychotic effect similar to that of electroconvulsive therapy because it could work as mild electroshock applied to sensory cortex. Additionally, cold shower is example of stress-induced analgesia and would also be expected to “crowd out” or suppress psychosis-related neurotransmission within mesolimbic system 47).

Cold exposure can activate components of reticular activating system such as locus ceruleus and raphe nuclei, which can result in activation of behavior and increased capacity of central nervous system (CNS) to recruit motoneurons 48). Cold exposure activates sympathetic nervous system; increase blood level of beta-endorphin and noradrenaline; and increase synaptic release of noradrenaline in brain. Antidepressive effect of cold shower attributed to presence of high density of cold receptors in skin expected to send an overwhelming amount of electrical impulses from peripheral nerve endings to the brain. It has significant analgesic effect and it does not cause dependence or noticeable side effects 49). Most narcotics administered rectally can cause intoxication. There is a significant co-morbidity of schizophrenia with intestinal illnesses and thus colon cleansing can significantly improve mental state 50).

Water therapy for arthritis

Walking in water at umbilical level increases the activity of erector spinae and activates rectus femoris to levels near to or higher than walking on dry ground 51). Osteoarthritis is one of the most prevalent musculoskeletal diseases in the world 52) Approximately 10% of the population aged 65 years and over present with osteoarthritis symptoms and more than half of the population have subclinical radiographic osteoarthritis 53). Exercise can be offered as water-based (hydrotherapy) or land-based exercises for hip and knee osteoarthritis 54). Water therapy is often recommended as a treatment option in the elderly population mostly because it is performed in a safer environment with a lower risk of falls than land-based exercises 55). Furthermore, patients with osteoarthritis show higher levels of treatment adherence with water physical therapy than other forms of conservative management 56). It is argued that water physical therapy offers additional physiological and biomechanical benefits compared to land-based exercises for patients with knee osteoarthritis and these could lead to better clinical outcomes. It is hypothesized that water physical therapy speeds patients’ early dynamic muscular strengthening and active mobilization even in the presence of severe pain 57). Furthermore, aquatic buoyancy potentially reduces weight-bearing stresses on joints, bones, and muscles. Hydrotherapy also allows the performance of closed-chain exercises, which are potentially painful with greater weight bearing 58). The results of this study 59) demonstrated that a structured six-week hydrotherapy program in conjunction with an educational program led to greater improvements in pain and function in the short term when compared to an educational program alone in women suffering from knee osteoarthritis. Furthermore, women with knee osteoarthritis who received hydrotherapy showed greater improvements in knee muscle performance such as knee flexor and extensor strength, knee flexor power, and knee extensor resistance. Water therapy exercises are usually advocated in the treatment of knee osteoarthritis because of the water properties, particularly those associated with buoyancy, which potentially reduces joint loading 60). Water pressure and temperature could also lead to an increased sensory input and further help in joint pain relief.

Musculoskeletal system

High performance athletes employ a variety of strategies with the intention of accelerating their recovery 61). Non-elite levels of athlete have also been shown to undertake a number of different recovery strategies post-exercise 62), potentially to decrease soreness and improve subsequent performance. The efficacy of numerous recovery strategies has been explored in scientific studies and also in practical sport applications, with some strategies being used without compelling supportive evidence 63).

Water immersion recovery strategies such as cold water immersion and contrast water therapy are used by athletes across a range of competition levels 64) to enhance post-exercise recovery 65). Cold water immersion reportedly minimises muscle oedema and provides analgesic effects post-exercise 66). Contrast water therapy is the alternation between hot and cold water 67) and is reported to decrease lactate accumulation 68), inflammation, edema, pain and muscle stiffness 69). The common explanation for contrast water therapy effectiveness is the pumping action of circulating blood, which is caused by alternation between vasodilation and vasoconstriction in response to hot and cold water 70).

Cold water immersions <59°F (<15°C) is one of the most popular intervention used after exercise 71), which significantly lowered ratings of fatigue and potentially improved ratings of physical recovery immediately after immersion with reduction in delayed onset muscle soreness at 24, 48, 72, and 96 hour follow-ups after exercise compared with passive interventions involving rest or no intervention 72).

Rate of decrease in plasma lactate concentration over 30 min recovery period after intense anaerobic exercise was significantly higher in contrast-head-out water immersions [hot 96.8 °F (36°C) and cold 53.6 °F (12°C)] compared with passive recovery on bed for both genders 73).

Leg immersion in warm water 111.2 ± 1°F (44 ± 1°C) for 45 min before stretch-shortening exercise reduced most of the indirect markers of exercise-induced muscle damage, including muscle soreness, creatine kinase activity in the blood, maximal voluntary contraction force, and jump height. Decreasing muscle damage did not improve voluntary performance, therefore clinical application of muscle prewarming may be limited 74).

Contrast water therapy (contrast water therapy) [alternating 1-min hot 100.4 °F (38°C) and 1-min cold 59 °F (15°C)] for 6/12/18 min lowered subjective measures of thermal sensation and muscle soreness compared with control (seated rest) but no consistent differences were observed in whole body fatigue. It indicates contrast water therapy for 6 min assisted acute recovery from high-intensity running and contrast water therapy duration did not have dose-response effect on running performance recovery 75). Contrast baths have been suggested for reducing pain; hand volume; and stiffness in affected extremities but it had no significant effect on pre- and/or postoperative hand volume in carpal tunnel syndrome 76).

Cold water or cold/thermoneutral water did not induce modifications of inflammatory and hematological markers. The performances of athletes were not negatively influenced by cold water immersions or contrast water therapy. Reduced perception of fatigue after training session was the principal effect of cold water immersions 77) because cold exposure increases opioid tone and high metabolic rate, which could diminish fatigue by reducing muscle pain and accelerating recovery of fatigued muscle, respectively 78), which can improve training and competitions in young soccer players 79).

A systematic review on management of fibromyalgia syndrome through hydrotherapy described as “there is strong evidence for the use of hydrotherapy in the management of fibromyalgia syndrome” and it showed positive outcomes for pain; tender point count; and health-status 80). Combination of sauna-therapy (once daily for 3 days/week) and underwater exercise (once daily for 2 days/week) for 12 weeks significantly reduced pain and symptoms (both short- and long-term); and improved quality of life in patients with fibromyalgia syndrome 81). Pool-based exercise using deep water running three times/week for 8 weeks is safe and effective intervention for fibromyalgia syndrome because it showed significant improvement in general health and quality of life compared with control; and significant improvement in fibromyalgia impact questionnaire score, incorporating pain; fatigue; physical function; stiffness; and psychological variables 82).

Hydrotherapy may have some short-term benefit to passive range of movement in rehabilitation after rotator cuff repair 83). Spa water 98.6 °F (37°C) and tap water heated to 98.6 °F (37°C) for the duration of 20 min/day for 5 days/week for the period of 2 weeks with home-based exercise program improved the clinical symptoms and quality of life in patient with osteoarthritis of knee. However, pain and tenderness statistically improved in spa water 84). It may be due to that spa waters are not only naturally warm, but their mineral content is also significant. Spa water has mechanical, thermal, and chemical effects.

In ankylosing spondilitis patients, balneotherapy statistically improved pain; physical activity; tiredness and sleep score; Bath Ankylosing Spondilitis Disease Activity Index (BASDAI); Nottingham Health Profile (NHP); patient’s global evaluation and physician’s global evaluation at 3 weeks, but only on modified Shober test and patient’s global evaluation parameters at 24 weeks. It indicates the effect of balneotherapy in improving disease activity and functional parameters in ankylosing spondilitis patients 85). Infrared sauna, a form of total-body hyperthermia was well tolerated; no adverse effects; and no exacerbation of disease were reported in patients with rheumatoid arthritis (RA) and ankylosing spondilitis in whom pain, stiffness, and fatigue showed clinical improvements during the 4 weeks treatment period but these did not reach statistical significance 86).

Aqua-jogging without caloric restrictions in obese persons for 6 weeks was associated with reductions in waist circumference and body fat; improvement of aerobic fitness and quality of life 87).

Water therapy exercises may be an excellent alternative to land exercise for individuals who lack confidence, have high risk of falling, or have joint pain 88). Water buoyancy reduces the weight that joints, bones, and muscles have to bear 89). Warmth and pressure of water also reduce swelling and reduces load on painful joints, remotes muscle relaxation 90). Water therapy exercises has significant effects on pain relief and related outcome measurements for locomotor diseases. Patients may become more active and improve their quality of life as a result of water therapy exercises 91). Water-based and land-based exercises reduced pain and improved function in patients with knee osteoarthritis and that water-based exercise was superior to land-based exercise for relieving pain before and after walking 92). Hydrotherapy is highly valued by rheumatoid arthritis patients who were treated with hydrotherapy (30-min session/week) reported feeling much better/very much better than those treated with land exercises (similar exercises on land) immediately on completion of the treatment program (6 weeks). But this benefit was not reflected on 10 m walk times, functional scores, quality of life measures, and pain scores by differences between groups 93). Hot compress with surrounding electro-acupuncture needling was significantly effective on rear thigh muscles strain and it was superior to conventional needling method and cupping in improving symptoms and physical signs as well as recovery of walking function of athletes 94).

Benefits of water exercise

Keeps joints moving

Pain in your joints may make you want to hold them very still as moving can be painful. However, immobilizing your joints or not using them will over time cause the joints, ligaments and muscles to lose range of motion and weaken. Muscles may also shorten and tighten up, causing you to feel more pain and stiffness and be less able to do the things you want to do.

Regular exercise helps keep joints moving, restores and preserves flexibility and strength, and protects joints against further damage. Exercise can also improve a person’s coordination, endurance and ability to perform daily tasks and can lead to an enhanced sense of self-esteem and accomplishment.

Exercising in water is a gentle way to exercise joints and muscles. The buoyancy of the water supports and lessens stress on the joints and encourages freer movement. Water may also act as resistance to help build muscle strength. Consult your doctor to determine whether water exercises are appropriate for you.


The use of heat is recommended for many people with arthritis, but not all. Your doctor can help you determine if it is appropriate for you. People whose arthritis symptoms respond well to heat have discovered many benefits. They have found that heat can to a great extent relax their muscles, decrease pain and stiffness and allow them to move through their exercises and daily activities with greater ease.

Warm water is an especially good way to deliver and distribute heat to many parts of the body. Extremely hot water is not safe and is not necessary to get results. Mild heat is just as effective and easier for the body to tolerate. The water temperature should feel soothing and comfortable, not hot. In a pool, water temperatures between 83 to 88 degrees are usually comfortable for people who are exercising. People who are just soaking or doing very gentle movements while sitting in a spa can usually tolerate higher temperatures. Soaking time will vary depending on the water temperature and an individual’s tolerance to heat. New spa users should vary the temperature and length of stay until they can determine what is most comfortable. Start slowly and extend the time in the spa as tolerated. For most people, soaking time should not exceed 10-15 minutes at temperatures between 98-104 degrees. Remember too that children and elderly persons are more prone to become overheated.

Doctors often advise that people with arthritis soak in warm water in the morning before beginning their daily activities. This is a time when many people find that pain and stiffness is at its worst. It may be just as beneficial to use spas or warm water pools at other times: in the afternoon to help relax muscles and joints after a full day of activities; to loosen muscles before doing exercises; in the evening before bedtime to bring on a restful sleep.

Gastrointestinal system

Drinking water significantly elevates the resting energy expenditure in adults but in overweight children transient decrease in resting energy expenditure was observed immediately after drinking 10 ml/kg cold water 39.2 °F (4°C). Then a subsequent rise in resting energy expenditure was observed, which was significant after 24 min and the maximal mean resting energy expenditure values were seen after 57 min, which was 25% higher than baseline. The recommended daily amount of water consumption in children could result in energy expenditure equivalent to additional weight loss of about 1.2 kg/year suggesting that water drinking could assist overweight children in weight loss or maintenance 95). Exposure to cold increases metabolic rate, for example, head-out immersion in cold water of 68 °F (20°C) almost doubles metabolic rate, while at 57.2 °F (14°C) it is more than quadrupled 96).

When very-hot compress applied to lumbar region of healthy female for 10-min blood flow to the back increased to 156% with increased blood flow to upper arm. Immediately after hot compress, bowel sounds increased 1.7 times compared with before application, which suggest that a very hot compress can be useful to promote flatus or defecation 97). Low mineral water intake normalizes the intestinal permeability of patients with atopic dermatitis 98).

Warm water is effective for colonic spasm in which significantly less discomfort was reported compared with control group and this may be useful as an alternative for glucagon (expensive) and hyoscyamine (has side effects) because it has no side effects and costs practically nothing 99).

In patients with acute anal pain due to hemorrhoids or anal fissures, neither cold water <59 °F (<15°C) nor hot water > 86 °F (>30°C) sitz bath did control pain statistically 100). Similarly, after sphincterotomy for anal fissure, sitz bath produced no significant difference in pain but significant relief in anal burning and better satisfaction score with no adverse effects were observed compared with control group 101). Healing and pain relief was not significant in sitz bath but it improved patient satisfaction in acute anal fissures 102).

Though there was no strong evidence to support the use of sitz bath for pain relief and to accelerate fissure or wound healing among adult patients with anorectal disorders, patients were satisfied with using sitz bath and no severe complications were reported 103). In contrast, warm-water sitz bath (104 °F [40°C], 113 °F [45°C], and 122 °F [50°C] for 10 min each time) in anorectal disorder, pain relief was more evident and lasted longer at higher bath temperatures. Pain relief after sitz bath might attribute to internal anal-sphincter relaxation, which might be due to thermosphincteric reflex, resulting in diminution of the rectal neck pressure. The higher the bath temperature, the greater the drop in rectal neck pressure and internal sphincter electromyographic activity, and longer the time needed to return to pretest levels 104).

In posthemorrhoidectomy care, water spray method could provide a safe and reliable alternative to sitz bath as a more convenient and satisfactory form of treatment 105).

Spa treatment with mineral water sulfate calcium induced clinical remission of the disease, normalization of the echoscopic picture of stomach and gallbladder, their motor function, tesiocrystalloscopic characteristics of saliva suggest its effectiveness in rehabilitation of patients with gastric and gallbladder motor-evacuatory dysfunction 106). Intake of sulfate-chloride-sodium mineral water activates regulation of carbohydrate metabolism by insulin and cortisol due to the formation of adaptive reactions. It promoted trophic effects of insulin and gastrin in animals with significant reduction in peptic ulcer size and enhanced resistance to stressful factors 107).

Immersion in Dead Sea water produced significant reduction in blood glucose in type-2 diabetes mellitus and no significant differences in insulin, cortisol, and c-peptide levels were observed between diabetes mellitus patients and healthy volunteers following immersion 108).

Genito urinary system

Mean labor pain scores were significantly higher in control group than immersion bath (immersion bath) group suggest that use of immersion bath as an alternative form of pain relief during labor 109). Head-out water immersions in primipara at any stage of labor, from 2 cm external opening of the uterine cervix, significantly decreased parturition duration compared with traditional delivery. It raised both the amplitude and frequency of uterine contractions proportional to uterine cervix gaping with no disturbances in contraction activity of the uterus. A 3-cm gaping of uterine cervix is the optimal timing for head-out water immersions in the primipara because earlier head-out water immersions at 2-cm uterine cervix gaping also accelerated the labor but required repetitions of head-out water immersions or use of oxytocin for correcting weakened uterine contraction 110).

In contrast, immersion bath did not influence the length of labor and uterine contractions frequency. However, contractions length was statistically shorter in immersion bath and it can be an alternative for woman’s comfort during labor, since it provides relief to her without interfering on labor progression or jeopardizing the baby 111).

Head-out water immersions during first stage of labor reduces the use of epidural/spinal/paracervical analgesia/anesthesia compared with controls and there is no evidence of increased adverse effects to fetus/neonate or woman from laboring in water or water birth 112). Neonatal swimming can accelerate babies growth in early stage 113). In a microbiological study, comparing neonatal bacterial colonization after water birth to conventional bed deliveries with or without relaxation bath showed no significant difference between three groups in neonatal outcome, infant’s and maternal infection rate 114).

Cold-sitz bath but not warm-sitz bath, significantly reduced edema during postepisiotomy period 115) and perineal pain, which was greatest immediately after the bath 116). Bakera, a steam bath prepared with various plants (commonly the essential oil plants) is traditionally used in Minahasa (Indonesia) mainly for recuperation after childbirth. It is based onthermotherapy with aromatherapy which attribute for its therapeutic effects. Thermotherapy soothes symptoms such as heaviness in limbs, edema, muscular strain, loss of appetite, and constipation. Essential oils of the plants used have antiseptic, antiphlogistic, and immunostimulant effect. Hence it can be an effective and safe method for recuperation after child birth 117). In postnatal mothers, alternate (hot and cold) compress and cold cabbage leaves were equally effective in reducing breast engorgement, but in relieving breast engorgement pain, alternate compresses were more effective than cold cabbage leaves 118).

Warm-sitz bath 104-113 °F (40-45°C) for 10 min, for at least 5 days immediately after the removal of Foley urethral catheter in patient undergone transurethral resection of prostate (TURP), significantly reduced urethral stricture compared with no sitz bath group who had 1.13-fold increased risk of re-hospitalization within 1 month after surgery due to postoperative complications compared with warm-sitz bath group 119). Thirty healthy volunteers and 21 patients with urinary retention after hemorrhoidectomy underwent sitz bath at 40°C, 45°C, and 50°C where the number of spontaneous micturitions increased with higher-temperature baths and it seems to be initiated by reflex (thermo-sphincter reflex) internal urethral sphincter relaxation. The urethral pressure both in normal and retention subjects showed significant reduction, which increased with higher temperature; and vesical pressure or EMG activity of the external urethral sphincter did not show significant differences 120).

Hematology and immunology

Subsequent cold exposure induced increase of leukocytes, granulocytes, circulating levels of interleukin (IL)-6, and natural killer (NK) cells and its activity. Leukocytes, granulocyte, and monocyte responses were augmented by pretreatment with exercise in water 64.4 °F (18°C) and thus acute-cold exposure has immune-stimulating effects 121).

Daily brief cold stress can increase both numbers and activity of peripheral cytotoxic T-lymphocytes and natural killer (NK) cells, the major effectors of adaptive and innate tumor immunity, respectively. It (for 8 days) improved survival of intracellular parasite Toxoplasma gondii infected mice, with consistent enhancement in cell-mediated immunity. The sustained/longer-term effects of cold stress repeated daily over the period of 5 days to 6 weeks increased plasma levels of tumor necrosis factor-α, IL-2, IL-6. A hypothesis describes, daily brief cold-water stress over many months could enhance antitumor immunity and improve nonlymphoid cancer survival rate. The possible mechanism of nonspecific stimulation of cellular immunity might attribute to transient activation of sympathetic nervous system, hypothalamic-pituitary-adrenal and hypothalamic-pituitary-thyroid axes. Though daily moderate cold hydrotherapy does not appear to have noticeable adverse effects on normal subjects, some studies showed that it can cause transient arrhythmias in patients with heart problems and can also inhibit humoral immunity. Sudden ice-cold head-out water immersions can produce transient pulmonary edema and increase blood-brain barrier permeability, thereby increasing mortality of neurovirulent infections. Studies are required to warrant this hypothesis for immunotherapy development for some (nonlymphoid) cancers, including those caused by viral infections 122).

Warm water 82.4 °F (28°C) treatment could not only cure bacterial cold-water disease but also immunize against causative agent Flavobacterium psychrophilum 123).

Head-out head-out water immersions 101.13 ± 0.04°F (38.41 ± 0.04°C) for 30 min decreased blood viscosity; red blood cells count; and mean hematocrit without significant changes in leukocytes and platelets count; mean corpuscular volume; plasma viscosity; erythrocyte filtration time and red cell deformability index 124). Application of hyper-thermic water bath produced significant reduction of relative B-lymphocyte. Whole-body hyperthermic water bath reduced relative total T-lymphocyte counts; increased relative CD8+ lymphocyte; NK cell counts and its activity, which were probably dependent on increased somatotropic hormone production 125).

Endocraine and hormonal system

During cold exposure increase levels of circulating norepinephrine was observed 126) and exercising hypothalamic-pituitary-adrenal system by repeated cold exposure could potentially restore its normal function in chronic fatigue syndrome, or at least increase net hypothalamic-pituitary-adrenal activity (without changing baseline activity) 127). It produces temporary increase in plasma levels of adrenocorticotropic hormone (ACTH), beta-endorphin, and cortisol 128). The sustained/longer-term effects of cold stress repeated daily produced increase in ACTH, corticosterone, and decrease in α-1-antitrypsin and testosterone 129). Cold stress reduces level of serotonin in most regions of brain (except brainstem) 130). Cold stress-induced analgesia might be mediated by increased production of opioid peptide beta-endorphin (an endogenous pain-killer) 131).

Exposure to sauna and ice-head-out water immersions significantly elevated epinephrine levels in winter swimmer 132). Steam bath produced increase in blood serum concentrations of gastric and aldosterone, with decrease in concentrations of cortisol in athlete-fighters 133). Whole-body hyperthermic bath increased sauna-therapyH activity in 8 out of 10 volunteers 134).

Eye, skin, and hair

Warm moist air device seems to be safe and produced improvement in tear stability and symptomatic relief in ocular fatigue in patients with meibomian gland dysfunction 135). Sauna 176 °F (80°C) produced stable epidermal barrier function; increase in stratum corneum hydration; faster recovery of both elevated water loss and skin pH; decrease in casual skin sebum content on skin surface of forehead; increase in ionic concentration in sweat and epidermal blood perfusion in volunteers. It suggests protective effect of sauna-therapy on skin physiology 136). Clinical remission of atopic dermatitis has been reported after intake of low-salt water 137). Application of heated mustard compress produced second-degree, partial-thickness burn followed by hyperpigmentation and hypertrophic scarring 138). Persistent use of cold pillow compress could reduce hair follicles inhibition or damage caused by chemotherapeutic agents. So alopecia can be decreased or prevented 139).

Temperature regulation

Very-hot compress applied to lumbar region of healthy female for 10 min increased back skin temperature to 105.98-109.58 °F (41.1-43.1°C) under hot compress, followed by decreased rapidly but no changes observed in body temperature 140). A case of 20% of 2nd degree burns and severe heat stroke followed by temperature rose up to 104.9 °F (40.5°C) and patient developed severe multiorgan failure and critical polyneuropathy was reported after exposure to extreme heat in sauna for unknown period of time 141). The most effective method of reducing body core temperature appears to be immersion in iced water, main predictor of outcome in exertional heatstroke is the duration and degree of hyperthermia where possible patients should be cooled using iced-head-out water immersions, but if it is not possible, combination of other techniques may be used to facilitate rapid cooling 142) such as fan-therapy, Chead-out water immersions, iced-baths, and evaporative cooling 143).

Wet-ice, dry-ice, and cryogen packs applied to skin overlying right triceps surae muscle for 15 min on 10 females decreased mean skin temperature 53.6 °F (12°C), 49.82 °F (9.9°C), and 45.14 °F (7.3°C), respectively. None of the modalities produced skin temperature cooling below 62.6 °F (17°C) and no cooling was demonstrated 1 cm proximal or distal to any modalities after 15 min of application. Significant mean skin temperature reduction in between pretreatment rest interval (time 0) and 15 min after removal of modality (time 30) was observed only in wet-ice. It suggests wet-ice was significantly more efficient in reducing skin temperature than dry-ice and cryogen packs 144).

After exercise at 65% maximal oxygen consumption at ambient temperature of 102.2 °F (39°C) until rectal temperature increased to 104 °F (40°C) produced no difference in cooling rate between head-out water immersions at 46.4 °F (8°C), 57.2 °F (14°C), and 68 °F (20°C) but cooling rate was significantly greater during 35.6 °F (2°C), which was almost twice as much as other conditions. It suggests that 35.6 °F (2°C) head-out water immersions is the most effective treatment for exercise-induced hyperthermia 145). When hyperthermic individuals are immersed in 35.6 °F (2°C) water for approximately 9 min to rectal temperature cooling limit of (38.6°C) negated any risk associated with overcooling 146).

Whole body immersion in moderately cold water is effective cooling maneuver for lowering body temperature and body heat content of approximately 545 kJ at the end of immersion in absence of severe physiological responses generally associated with sudden cold stress 147). Significant less body temperature variability and an overall higher body temperature were observed in late preterm infants following tub bathing procedure 148).

How to do water therapy

Water therapy exercises

Exercises in water can be most helpful and enjoyable for people with arthritis. Water can provide warmth and support (buoyancy) which can facilitate the exercising of joints affected by arthritis. Spas can provide ready access to warm water exercises in the home. Soaking in warm water allows muscles to become relaxed which can then make it easier to perform exercises and carry out daily tasks. Relaxed muscles can also create an overall feeling of comfort. Pools also enable people with arthritis to relax and exercise their joints often in the company of others. Pools offer more space than spas, allowing for a wider variety and more vigorous exercises.

Warm water exercises

When first entering a spa or pool, relax and enjoy the soothing water. When your muscles and joints feel more comfortable and relaxed, slowly begin your exercise routine. Allow enough time after exercising to again relax muscles before getting out of the water.

The Arthritis Foundation recommends the following guidelines when doing water exercises:

  • Submerge body part being exercised.
  • Move the body part slowly and gently.
  • Begin and end with easy exercises.
  • Follow through complete joint range of motion if possible, but do not force movement. Stop if you experience any sudden or increased pain.
  • Do three to eight repetitions as tolerated.
  • Pain that lasts for more than one to two hours after exercise may indicate overuse. Cut back next time.
  • Remember the weakening effects of heat when exercising in warm water.
  • Start slowly and don’t overdo.
  • Any individuals who have severe joint damage or joint replacement should check with their doctor or surgeon before doing any of the following exercises.

The following illustrations of exercises can be done while sitting in a spa or while sitting or standing in a pool. Consult your doctor or physical therapist to determine which exercises are appropriate for you.


Forward arm reach (flexion):

  • Raise one or both arms forward and upward as high as possible. If one arm is very weak, you can help it with the other arm. See figure 1.

Figure 1. Forward arm reach

water exercise - forward arm reach

Sideways arm reach (abduction):

  • Slowly raise both arms out to the side, keeping the palms down. Raise only to shoulder (water) level. Then lower arms. See figure 2.

Figure 2. Sideways arm reach

water exercise - sideways arm reach

Arm circles (combined motions):

Raise both arms forward until they are a few inches below water level. Keep both elbows straight. Make small circles (about the size of a softball) with the arms. Gradually increase circle size (until the size of a basketball). Then decrease. First make inward, then outward circles. Do not raise your arms out of the water or let them cross. See figure 3.

Figure 3. Arm circles

water exercise - arm circles


Elbow bend (flexion/extension):

  • Bend the elbows and the thumbs to the shoulders. You do not have to touch. Relax elbows and straighten down along side of you.

Elbow bend and turn (combined motion):

  • Turn the arms until the palms face forward. Bend the elbows until the fingertips touch the shoulders. Relax and straighten your elbows leading down with your palms.

Wrist and fingers

Wrist turn (supination/pronation):

  • Turn the palms toward the ceiling, then turn them down to face the bottom of the spa or pool.

Wrist bend (flexion/extension):

  • Bend the wrists backward and then forward.

Hand and fingers

Finger hold (thumb opposition):

  • Touch the tip of the left thumb to the tips of the other fingers one at a time to form a round letter “O”. Repeat with right thumb. (May move both thumbs at the same time.)

Finger curl (flexion/extension):

  • Curl the fingers into the palm (making a loose fist) and then straighten them out.

Thumb circles (circumduction):

  • Move the thumb in a large circle.

Ankle and toes

Ankle bend:

  • Sit with back supported and slowly straighten your knee. While holding the knee straight, bend the ankle and point the toes. Then reverse to point them toward the ceiling.

Toe curl (flexion/extension):

  • Curl right toes down and then straighten them out. Repeat with left foot.

Ankle circles (dorsiflexion/plantar flexion and inversion/eversion):

  • Sit with back supported and slowly straighten your knee. While holding the knee straight, make large inward circles with the foot moving from the ankle. Then repeat circles in the opposite direction. Repeat with other foot.

Hip and knee

Knee bend (flexion/extension):

  • Slowly raise one foot up to straighten out your knee. Hold straight 3 seconds.

Knee to chest (combined stretch):

  • Sit erect. Lift one knee and hug towards chest, hands under the thighs or over the knee to assist with the stretch.

Spread eagle hip (abduction with knee extension):

  • Sitting on the edge of the seat, straighten one knee. While holding it straight, slowly move it out to the side, hold 3 seconds then bring it back to the center. Repeat with other leg.

Leg swing (hip flexion/extension):

  • Stand with left side to pool wall, holding wall with left hand for balance. Keep knees straight. Lift right leg slowly forward to a comfortable height. If possible, hold leg for a count of 5 seconds, then slowly swing leg backward. Motion should only occur in hip (not waist or neck). Keep upper body straight at all times. Repeat with left leg–right side to wall.

Knee lift (hip and knee flexion/extension):

  • Stand with back or left side against pool wall. Bend right knee, bringing thigh parallel to water surface. Straighten the knee; then bend it again. Lower leg, keeping knee bent. Repeat on left.

Calf stretch:

  • Stand with left side to wall, holding wall with left hand for balance. Stand straight with legs slightly apart and left leg forward of right. Keeping body straight, lean forward slowly letting left knee bend. Keep right knee straight and heel on bottom. Return to starting position. Repeat with right leg forward, right side to pool.

Side leg lift (hip abduction and adduction):

  • Stand with left side to pool wall, holding wall with left hand for balance, knees relaxed. Swing right leg out toward center of pool and back to midline. Do not cross in front of left leg. Repeat with left leg–right side to wall.


  • Walk normally across or in a circle in the pool. Swing your arms as you walk.


Side bend (flexion):

  • Place hands on hips and without moving your feet, bend slowly toward the right; then return to starting position and bend to the left. Do not twist or turn the trunk. Arms may hang at the side if preferred and as you lean to the right, let the right hand slide down the thigh. Repeat on the left.

Cold water immersion

The effect of cold water immersion on delayed onset muscle soreness and perceived fatigue was significant, but the effect size was small in terms of delayed onset muscle soreness. A previous meta-analysis indicated that cold water immersion induced a significant effect that was still observable at 96 h after exercise when compared with passive recovery 149). In the same publication, a lower rating of perceived fatigue was observed after cold water immersion 150). The improvement in overall fatigue through the use of cold water immersion has been reported in several circumstances after training and competition (e.g., soccer tournaments or basketball matches) 151). Another meta-analysis showed a positive effect of cold water immersion on lowering delayed onset muscle soreness after strenuous exercise in trained athletes and in untrained subjects or those who exercised recreationally 152). An exposure of 51.8-59 °F (11–15 °C) over 11–15 min was considered to be the optimal circumstance to obtain a positive impact of cold water immersion after exercise to reduce delayed onset muscle soreness 153). In this meta-analysis 154), the authors were able to detect significant differences depending on the water temperature. They observed that only immersion in water with a temperature lower than 59 °F (15°C) had a positive impact on inflammation. Depending on the type of exercise, the duration of immersion, the level of immersion and the water temperature, the outcomes were sometimes at variance.

Several mechanisms have been presented to explain the benefits of cold water immersion on recovery 155). A common explanation of the impact of cold water immersion on delayed onset muscle soreness and fatigue is a reduction in exercise-induced inflammation and muscle damage. Dupuy et al. 156) found a significant positive effect of cold water immersion on the creatine kinase concentration in the blood after intensive exercise, but the effect size was small. A moderate decrease of circulating creatine kinase has previously been reported with the use of cold water immersion after exercise 157). Both the level of immersion and the cold temperature of the water may reduce the formation of swelling and pain sensation after exhaustive physical exercise 158). Hydrostatic pressure may facilitate the transport of fluids from the muscle to the blood and therefore eliminate metabolites 159). Vasoconstriction due to cold temperature may also reduce fluid diffusion into the interstitial space 160) and locally diminish the inflammatory reaction 161), which in turn may reduce the feeling of pain 162). Cold alone has also a direct analgesic impact 163). However, some other authors did not detect any changes in the creatine kinase concentration after the use of cold water immersion following exhaustive physical exercise 164). No significant effect was observed in this meta-analysis 165) concerning changes in IL-6 and CRP concentrations in the blood. A similar observation has already been presented 166).

Contrast water therapy

Contrast water therapy is often used for recovery purposes and consists of bathing alternately in warm and cold water. We found that contrast water therapy had a significant impact on delayed onset muscle soreness (though the effect size was small) but not on perceived fatigue. A systematic review has previously expressed the significant impact of using this technique to improve recovery 167). A more recent work also showed the effectiveness of this technique after various forms of exhaustive and damaging exercises 168). Contrast water therapy was also able to significantly reduce the perception of pain at 24, 48, and 72 h post-eccentric exercise 169). Alternating therapy with cold and warm water immersion induces successive peripheral vasoconstriction and vasodilation 170) and may reduce the formation of oedema after exercise, influence inflammatory pathways and decrease the feeling of pain 171). Additionally, in this meta-analysis 172), the authors found that contrast water therapy reduced creatine kinase concentrations in the blood, indicating reduced muscle damage.

Compression garments

Similar to massage, both the use of compression garments and cold water immersion induced a significant and positive impact on delayed onset muscle soreness and perceived fatigue but had a less pronounced effect. It has been previously reported in a narrative review 173) and meta-analysis 174) that the use of compressive garments after damaging exercise affected delayed onset muscle soreness. Moreover, recent works confirmed these findings and showed that the effects were still significant at 96 h after exercise 175). This study 176) confirmed the significant impact of compression garments on delayed onset muscle soreness at 96 hour after exercise. The authors also found a significant decrease in perceived fatigue when compression garments were used. It has been shown that wearing a whole-body compression garment over a 24-h period after intense heavy resistance training significantly reduces perceived fatigue 177). The beneficial effect of compression garments on delayed onset muscle soreness and perceived fatigue might be explained by a possible reduction in the space available for swelling and oedema due to the compression applied to the limb, smaller changes in osmotic pressure that might diminish fluid diffusion in the interstitial space and better venous return 178).

It has been suggested that using a compression garment may also reduce exercise-induced muscle damage and inflammation 179). However, in our meta-analysis, we did not observe any significant changes in creatine kinase, IL-6, or CRP concentrations after the use of compression garments following exercise. This result is in contrast with a former meta-analysis that found that the use of compression garments was effective for reducing the creatine kinase concentration 180). Additionally, in the scientific literature concerning creatine kinase concentration and compression garments, there is a very wide range of study protocols. Some discrepancies in the findings exist and may nevertheless be explained by the different recovery period lengths, the lengths of the applied compression 181), the amount of pressure applied and the place (upper limbs, lower limbs, and even on whole-body) where the compression is applied 182). Additionally, individual variability in the sensitivity to blood flow changes may also be of importance 183). Similar remarks can be made for the absence of changes in IL-6 and CRP concentrations. Moreover, it previously been expressed that in the majority of the published works concerning the use of compression garments, the exercise protocols were not intense enough to induce a sufficient degree of muscle damage 184).

Water therapy summary

Based on available literature, water therapy or hydrotherapy was widely used to improve immunity and for the management of pain, heart failure, heart attack, chronic obstructive pulmonary diseases (COPD), asthma, Parkinson’s disease, ankylosing spondilitis, rheumatoid athritis, osteoarthritis of knee, fibromyalgia syndrome, anorectal disorders, fatigue, anxiety, obesity, hypercholesterolemia, hyperthermia, labor, etc. It produces different effects on various systems of the body depending on the temperature of water and though these effects are scientifically evidence based, there is lack of evidences for the mechanism on how hydrotherapy improves these diseases, which is one of the limitations of hydrotherapy, and further studies are required to find the mechanism of hydrotherapy on various diseases.

References   [ + ]