What is considered low blood pressure

Low blood pressure or hypotension is a reading of 90/60 mmHg or less. Normal blood pressure in adults is 120/80 mmHg or lower. Low blood pressure  (lower than 90/60 mmHg) might seem desirable and for some people, it causes no problems. Your body is very sensitive to changes in blood pressure. For example, if you stand up quickly, your blood pressure may drop for a short time. Your body adjusts your blood pressure to make sure enough blood and oxygen are flowing to your brain, kidneys, and other vital organs. However, for many people, abnormally low blood pressure (hypotension) can cause dizziness and fainting. In severe cases, low blood pressure can be life-threatening.

Blood pressure is the force of your blood pushing against the walls of your arteries. Each time your heart beats, it pumps out blood into the arteries. Your blood pressure is highest when your heart beats, pumping the blood. This is called systolic pressure. When your heart is at rest, between beats, your blood pressure falls. This is the diastolic pressure. Your blood pressure reading uses these two numbers. Usually they’re written one above or before the other, such as 120/80 mmHg. The mmHg is millimeters of mercury—the units used to measure blood pressure. Blood pressure doesn’t stay the same all the time. It lowers as you sleep and rises when you wake up. Blood pressure also rises when you’re excited, nervous, or active.

Some people have low blood pressure (lower than 90/60 mmHg) all the time. They have no symptoms and their low blood pressure are normal for them. In other people, blood pressure drops below normal because of a medical condition or certain medicines. As a result, less blood and oxygen flow to the body’s organs. These people may have symptoms of low blood pressure when standing up too quickly (postural hypotension or orthostatic hypotension). Low blood pressure is a problem only if it causes dizziness, fainting or in extreme cases, shock.

Types of low blood pressure

Doctors often break down low blood pressure (hypotension) into categories, depending on the causes and other factors. Some types of low blood pressure include:

• Low blood pressure on standing up (orthostatic, or postural, hypotension). This is a sudden drop in blood pressure when you stand up from a sitting position or after lying down. Gravity causes blood to pool in your legs when you stand. Ordinarily, your body compensates by increasing your heart rate and constricting blood vessels, thereby ensuring that enough blood returns to your brain. But in people with orthostatic hypotension, this compensating mechanism fails and blood pressure falls, leading to dizziness, lightheadedness, blurred vision and even fainting. Orthostatic hypotension can occur for various reasons, including dehydration, prolonged bed rest, pregnancy, diabetes, heart problems, burns, excessive heat, large varicose veins and certain neurological disorders. A number of medications also can cause orthostatic hypotension, particularly drugs used to treat high blood pressure — diuretics, beta blockers, calcium channel blockers and angiotensin-converting enzyme (ACE) inhibitors — as well as antidepressants and drugs used to treat Parkinson’s disease and erectile dysfunction. Orthostatic hypotension is especially common in older adults, but it also affects young, otherwise healthy people who stand up suddenly after sitting with their legs crossed for long periods or after squatting for a time. It’s also possible to have delayed orthostatic hypotension, with signs and symptoms developing 5 to 10 minutes after a change in posture. This might be a milder form of the condition, or it could be an early stage of it.
• Low blood pressure after eating (postprandial hypotension). This sudden drop in blood pressure after eating affects mostly older adults. Blood flows to your digestive tract after you eat. Ordinarily, your body increases your heart rate and constricts certain blood vessels to help maintain normal blood pressure. But in some people these mechanisms fail, leading to dizziness, faintness and falls. Postprandial hypotension is more likely to affect people with high blood pressure or autonomic nervous system disorders such as Parkinson’s disease. Lowering the dose of blood pressure drugs and eating small, low-carbohydrate meals might help reduce symptoms.
• Low blood pressure from faulty brain signals (neurally mediated hypotension). This disorder, which causes a blood pressure drop after standing for long periods, mostly affects young adults and children. It seems to occur because of a miscommunication between the heart and the brain.
• Low blood pressure due to nervous system damage (multiple system atrophy with orthostatic hypotension). Also called Shy-Drager syndrome, this rare disorder causes progressive damage to the autonomic nervous system, which controls involuntary functions such as blood pressure, heart rate, breathing and digestion. It’s associated with having very high blood pressure while lying down.

Low blood pressure signs and symptoms

For some people, low blood pressure signals an underlying problem, especially when it drops suddenly or is accompanied by signs and symptoms such as:

• Dizziness or lightheadedness
• Fainting (syncope)
• Blurred vision
• Nausea
• Fatigue
• Lack of concentration

Shock

Shock is a life-threatening condition that occurs when the body is not getting enough blood flow. Lack of blood flow means that the cells and organs do not get enough oxygen and nutrients to function properly. Many organs can be damaged as a result. Shock requires immediate treatment and can get worse very rapidly. As many 1 in 5 people who suffer shock will die from it.

The main types of shock include:

• Cardiogenic shock (due to heart problems)
• Hypovolemic shock (caused by too little blood volume)
• Anaphylactic shock (caused by allergic reaction)
• Septic shock (due to infections)
• Neurogenic shock (caused by damage to the nervous system)
• Vasodilatory shock

Cardiogenic shock

Cardiogenic shock is a major decrease in the heart’s ability to pump blood also can cause shock. Cardiogenic shock occurs if the heart suddenly can’t pump enough oxygen-rich blood to the body. The most common cause of cardiogenic shock is damage to the heart muscle from a severe heart attack.

This damage prevents the heart’s main pumping chamber, the left ventricle, from working well. As a result, the heart can’t pump enough oxygen-rich blood to the rest of the body.

In about 3 percent of cardiogenic shock cases, the heart’s lower right chamber, the right ventricle, doesn’t work well. This means the heart can’t properly pump blood to the lungs, where it picks up oxygen to bring back to the heart and the rest of the body.

Without enough oxygen-rich blood reaching the body’s major organs, many problems can occur. For example:

• Cardiogenic shock can cause death if the flow of oxygen-rich blood to the organs isn’t restored quickly. This is why emergency medical treatment is required.
• If organs don’t get enough oxygen-rich blood, they won’t work well. Cells in the organs die, and the organs may never work well again.
• As some organs stop working, they may cause problems with other bodily functions. This, in turn, can worsen shock. For example:
• If the kidneys aren’t working well, the levels of important chemicals in the body change. This may cause the heart and other muscles to become even weaker, limiting blood flow even more.
• If the liver isn’t working well, the body stops making proteins that help the blood clot. This can lead to more bleeding if the shock is due to blood loss.

How well the brain, kidneys, and other organs recover will depend on how long a person is in shock. The less time a person is in shock, the less damage will occur to the organs. This is another reason why emergency treatment is so important.

Causes of cardiogenic shock

The underlying causes of cardiogenic shock are conditions that weaken the heart and prevent it from pumping enough oxygen-rich blood to the body.

Heart Attack

Most heart attacks occur as a result of coronary heart disease (coronary artery disease). Coronary artery disease is a condition in which a waxy substance called plaque narrows or blocks the coronary (heart) arteries.

Plaque reduces blood flow to your heart muscle. It also makes it more likely that blood clots will form in your arteries. Blood clots can partially or completely block blood flow.

Conditions Caused by Heart Attack

Heart attacks can cause some serious heart conditions that can lead to cardiogenic shock. One example is ventricular septal rupture. This condition occurs if the wall that separates the ventricles (the heart’s two lower chambers) breaks down.

The breakdown happens because cells in the wall have died due to a heart attack. Without the wall to separate them, the ventricles can’t pump properly.

Heart attacks also can cause papillary muscle infarction or rupture. This condition occurs if the muscles that help anchor the heart valves stop working or break because a heart attack cuts off their blood supply. If this happens, blood doesn’t flow correctly between the heart’s chambers. This prevents the heart from pumping properly.

Other Heart Conditions

Serious heart conditions that may occur with or without a heart attack can cause cardiogenic shock. Examples include:

• Myocarditis. This is inflammation of the heart muscle.
• Endocarditis. This is an infection of the inner lining of the heart chambers and valves.
• Life-threatening arrhythmias. These are problems with the rate or rhythm of the heartbeat.
• Pericardial tamponade. This is too much fluid or blood around the heart. The fluid squeezes the heart muscle so it can’t pump properly.

Pulmonary Embolism

Pulmonary embolism (PE) is a sudden blockage in a lung artery. This condition usually is caused by a blood clot that travels to the lung from a vein in the leg. PE can damage your heart and other organs in your body.

Hypovolemic shock is a severe loss of blood or fluids from the body also can cause shock. Hypovolemic shock can happen as a result of:

• Major external bleeding (for example, from a severe cut or injury)
• Major internal bleeding (for example, from a ruptured blood vessel or injury that causes bleeding inside the body)
• Major loss of body fluids from severe burns
• Severe swelling of the pancreas (an organ that produces enzymes and hormones, such as insulin)
• Severe diarrhea
• Severe kidney disease
• Overuse of diuretics

Septic shock is severe infections causing shock. It can occur if bacteria enter the bloodstream. The bacteria release a toxin (poison) that leads to a dangerous drop in blood pressure.

Vasodilatory shock is a sudden and extreme relaxation of the arteries linked to a drop in blood pressure also can cause shock. It can occur due to:

• A severe head injury
• A reaction to certain medicines
• Liver failure
• Poisoning
• A severe allergic reaction (called anaphylactic shock)

Causes of shock

Shock can be caused by any condition that reduces blood flow, including ¹:

• Heart problems (such as heart attack or heart failure)
• Low blood volume (as with heavy bleeding or dehydration)
• Changes in blood vessels (as with infection or severe allergic reactions)
• Certain medicines that significantly reduce heart function or blood pressure

Shock is often associated with heavy external or internal bleeding from a serious injury. Spinal injuries can also cause shock.

Toxic shock syndrome is an example of a type of shock from an infection.

Symptoms of shock

A person in shock has extremely low blood pressure. Depending on the specific cause and type of shock, symptoms will include one or more of the following:

• Anxiety or agitation/restlessness
• Bluish lips and fingernails
• Chest pain
• Confusion, especially in older people
• Dizziness, lightheadedness, or faintness
• Pale, cool, clammy skin
• Low or no urine output
• Profuse sweating, moist skin
• Rapid but weak pulse
• Rapid, shallow breathing
• Unconsciousness

First Aid

Take the following steps if you think a person is in shock ²:

• Call your local emergency number for immediate medical help.
• Check the person’s airway, breathing, and circulation. If necessary, begin rescue breathing and CPR (cardiopulmonary resuscitation).
• Even if the person is able to breathe on their own, continue to check rate of breathing at least every 5 minutes until help arrives.
• If the person is conscious and does NOT have an injury to the head, leg, neck, or spine, place the person in the shock position. Lay the person on the back and elevate the legs about 12 inches (30 centimeters). Do NOT elevate the head. If raising the legs will cause pain or potential harm, leave the person lying flat.
• Give appropriate first aid for any wounds, injuries, or illnesses.
• Keep the person warm and comfortable. Loosen tight clothing.

IF THE PERSON VOMITS OR DROOLS

• Turn the head to one side to prevent choking. Do this as long as you do not suspect an injury to the spine.
• If a spinal injury is suspected, “log roll” the person instead. To do this, keep the person’s head, neck, and back in line, and roll the body and head as a unit.

DO NOT

In case of shock:

• Do NOT give the person anything by mouth, including anything to eat or drink.
• Do NOT move the person with a known or suspected spinal injury.
• Do NOT wait for milder shock symptoms to worsen before calling for emergency medical help.

When to Contact a Medical Professional

Call your local emergency number any time a person has symptoms of shock. Stay with the person and follow the first aid steps until medical help arrives.

Prevention of shock

Learn ways to prevent heart disease, falls, injuries, dehydration, and other causes of shock. If you have a known allergy (for example, to insect bites or stings), carry an epinephrine pen. Your health care provider will teach you how and when to use it.

What causes low blood pressure

Your blood pressure can vary depending on the time of day – it gradually increases throughout the day. What you’re doing and how you’re feeling can also affect it.

There are many possible causes of low blood pressure. It may be low because you’re fit and healthy, or you may have inherited it from your parents.

Some people develop low blood pressure as they get older.

It can also be caused by:

• Being pregnant, because the circulatory system expands rapidly during pregnancy, blood pressure is likely to drop. This is normal, and blood pressure usually returns to your pre-pregnancy level after you’ve given birth.
• Medical conditions, such as diabetes
• Heart problems. Some heart conditions that can lead to low blood pressure include extremely low heart rate (bradycardia), heart valve problems, heart attack and heart failure.
• Endocrine problems. Thyroid conditions such as parathyroid disease, adrenal insufficiency (Addison’s disease), low blood sugar (hypoglycemia) and, in some cases, diabetes can trigger low blood pressure.
• Dehydration. When your body loses more water than it takes in, it can cause weakness, dizziness and fatigue. Fever, vomiting, severe diarrhea, overuse of diuretics and strenuous exercise can lead to dehydration.
• Blood loss. Losing a lot of blood, such as from a major injury or internal bleeding, reduces the amount of blood in your body, leading to a severe drop in blood pressure.
• Severe infection (septicemia). When an infection in the body enters the bloodstream, it can lead to a life-threatening drop in blood pressure called septic shock.
• Severe allergic reaction (anaphylaxis). Common triggers of this severe and potentially life-threatening reaction include foods, certain medications, insect venoms and latex. Anaphylaxis can cause breathing problems, hives, itching, a swollen throat and a dangerous drop in blood pressure.
• Lack of nutrients in your diet. A lack of the vitamins B-12 and folate can keep your body from producing enough red blood cells (anemia), causing low blood pressure.
• Some types of medication
• Orthostatic hypotension

Medications that can cause low blood pressure

Some medications can cause low blood pressure, including:

• Water pills (diuretics), such as furosemide (Lasix) and hydrochlorothiazide (Maxzide, Microzide, others)
• Alpha blockers, such as prazosin (Minipress)
• Beta blockers, such as atenolol (Tenormin) and propranolol (Inderal, Innopran XL, others)
• Drugs for Parkinson’s disease, such as pramipexole (Mirapex) or those containing levodopa
• Certain types of antidepressants (tricyclic antidepressants), including doxepin (Silenor) and imipramine (Tofranil)
• Drugs for erectile dysfunction, including sildenafil (Revatio, Viagra) or tadalafil (Adcirca, Cialis), particularly when taken with the heart medication nitroglycerin

Orthostatic hypotension

Orthostatic hypotension also called postural hypotension, is a sudden fall in blood pressure that occurs when a person stand up from sitting or lying down position ³. Orthostatic hypotension can make you feel dizzy or lightheaded, and maybe even faint.

Orthostatic hypotension may be mild and last for less than a few minutes. However, long-lasting orthostatic hypotension can signal more-serious problems, so it’s important to see a doctor if you frequently feel lightheaded when standing up.

Occasional (acute) orthostatic hypotension is usually caused by something obvious, such as dehydration or lengthy bed rest, and is easily treated. Chronic orthostatic hypotension is usually a sign of another health problem, so treatment varies.

The prognosis for individuals with orthostatic hypotension depends on the underlying cause of the condition.

Symptoms of orthostatic hypotension

The most common symptom is lightheadedness or dizziness when you stand up after sitting or lying down. Symptoms usually last less than a few minutes.

Orthostatic hypotension signs and symptoms include:

• Feeling lightheaded or dizzy after standing up
• Blurry vision
• Weakness
• Fainting (syncope)
• Confusion
• Nausea

Causes of orthostatic hypotension

When you stand up, gravity causes blood to pool in your legs and abdomen. This decreases blood pressure because there’s less blood circulating back to your heart.

Normally, special cells (baroreceptors) near your heart and neck arteries sense this lower blood pressure. The baroreceptors send signals to centers in your brain, which signals your heart to beat faster and pump more blood, which stabilizes blood pressure. These cells also narrow the blood vessels and increase blood pressure.

Orthostatic hypotension is due to a lesion of the baroreflex loop, which senses a change in blood pressure and adjusts heart rate and activates sympathetic nerve system fibers to cause the blood vessels to narrow and correct low blood pressure.

Orthostatic hypotension may also be caused by hypovolemia (a decreased amount of blood in the body), resulting from the excessive use of diuretics, vasodilators, or other types of drugs, dehydration, or prolonged bed rest. The disorder may be associated with Addison’s disease, diabetes, and certain neurological disorders including Multiple System Atrophy with Orthostatic Hypotension (formerly known as Shy-Drager syndrome), autonomic system neuropathies, and other dysautonomias. Symptoms, which generally occur after sudden standing, include dizziness, lightheadedness, blurred vision, and syncope (temporary loss of consciousness).

Many different conditions can cause orthostatic hypotension, including:

• Dehydration. Dehydration is the most common cause of orthostatic hypotension. Dehydration occurs if the body loses more water than it takes in. Fever, vomiting, not drinking enough fluids, severe diarrhea and strenuous exercise with excessive sweating can all lead to dehydration, which decreases blood volume. Mild dehydration can cause symptoms of orthostatic hypotension, such as weakness, dizziness and fatigue.
• Heart problems. Some heart conditions that can lead to low blood pressure include extremely low heart rate (bradycardia), heart valve problems, heart attack and heart failure. These conditions prevent your body from responding rapidly enough to pump more blood when standing up.
• Endocrine problems. Thyroid conditions, adrenal insufficiency (Addison’s disease) and low blood sugar (hypoglycemia) can cause orthostatic hypotension, as can diabetes — which can damage the nerves that help send signals regulating blood pressure.
• Nervous system disorders. Some nervous system disorders, such as Parkinson’s disease, multiple system atrophy, Lewy body dementia, pure autonomic failure and amyloidosis, can disrupt your body’s normal blood pressure regulation system.
• After eating meals. Some people experience low blood pressure after eating meals (postprandial hypotension). This condition is more common in older adults.
• Pulmonary embolism. Pulmonary embolism (PE), is a sudden blockage in a lung artery. The blockage usually is caused by a blood clot that travels to the lung from a vein in the leg (deep vein thrombosis or DVT).
• Anemia. Anemia is a condition in which your blood has a lower than normal number of red blood cells. Anemia also can occur if your red blood cells don’t contain enough hemoglobin. Hemoglobin is an iron-rich protein that gives blood its red color. This protein helps red blood cells carry oxygen from the lungs to the rest of the body.
• Severe infections.

Risk factors for orthostatic hypotension

The risk factors for orthostatic hypotension include:

• Age. Orthostatic hypotension is common in those who are age 65 and older. Special cells (baroreceptors) near your heart and neck arteries that regulate blood pressure can slow as you age. It also may be harder for an aging heart to beat faster and compensate for drops in blood pressure.
• Medications. These include medications used to treat high blood pressure or heart disease, such as diuretics (water pills), alpha blockers, beta blockers, calcium channel blockers, angiotensin-converting enzyme (ACE) inhibitors and nitrates. Other medications that may increase your risk of orthostatic hypotension include medications used to treat Parkinson’s disease, certain antidepressants, certain antipsychotics, muscle relaxants, medications to treat erectile dysfunction and narcotics. Using medications that treat high blood pressure in combination with other prescription and over-the-counter medications may cause low blood pressure.
• Certain diseases. Some heart conditions, such as heart valve problems, heart attack and heart failure; certain nervous system disorders, such as Parkinson’s disease; and diseases that cause nerve damage (neuropathy), such as diabetes, increase the risk of low blood pressure.
• Heat exposure. Being in a hot environment can cause heavy sweating and possibly dehydration, which can lower your blood pressure and trigger orthostatic hypotension.
• Bed rest. If you have to stay in bed a long time because of an illness, you may become weak. When you try to stand up, you may experience orthostatic hypotension.
• Pregnancy. Because your circulatory system expands rapidly during pregnancy, blood pressure is likely to drop. This is normal, and blood pressure usually returns to your pre-pregnancy level after you’ve given birth.
• Alcohol. Drinking alcohol can increase your risk of orthostatic hypotension.

Complications of orthostatic hypotension

Persistent orthostatic hypotension can cause serious complications, especially in older adults. These include:

• Falls. Falling down as a result of fainting (syncope) is a common complication in people with orthostatic hypotension.
• Stroke. The swings in blood pressure when you stand and sit as a result of orthostatic hypotension can be a risk factor for stroke due to the reduced blood supply to the brain.
• Cardiovascular diseases. Orthostatic hypotension can be a risk factor for cardiovascular diseases and complications, such as chest pain, heart failure or heart rhythm problems.

Diagnosis of orthostatic hypotension

Your doctor’s goal in evaluating orthostatic hypotension is to find the underlying cause, and determine appropriate treatment for any health problems that may cause your low blood pressure. The cause isn’t always known.

Your doctor may review your medical history, review your symptoms and conduct a physical examination to help diagnose your condition.

Your doctor also may recommend one or more of the following:

• Blood pressure monitoring. Your doctor will measure your blood pressure both while you’re sitting and while you’re standing and will compare the measurements. Your doctor will diagnose orthostatic hypotension if you have a drop of 20 millimeters of mercury (mm Hg) in your systolic blood pressure or a drop of 10 mm Hg in your diastolic blood pressure within two to five minutes of standing up, or if standing causes signs and symptoms.
• Blood tests. These can provide information about your overall health, including low blood sugar (hypoglycemia) or low red blood cell levels (anemia), both of which can cause low blood pressure.
• Electrocardiogram (ECG or EKG). This noninvasive test detects irregularities in your heart rhythm or heart structure, and problems with the supply of blood and oxygen to your heart muscle. During this painless, noninvasive test, soft, sticky patches (electrodes) are attached to the skin of your chest, arms and legs. The patches detect your heart’s electrical signals while a machine records them on graph paper or displays them on a screen. Sometimes, heart rhythm abnormalities come and go, and an ECG won’t find any problems. If this happens, you may be asked to wear a 24-hour Holter monitor to record your heart’s electrical activity as you go about your daily routine.
• Echocardiogram. In this noninvasive exam, sound waves are used to produce a video image of your heart. Sound waves are directed at your heart from a wandlike device (transducer) that’s held on your chest. The sound waves that bounce off your heart are reflected through your chest wall and processed electronically to provide video images of your heart in motion to detect underlying structural heart disease.
• Stress test. A stress test is performed while you’re exercising, such as walking on a treadmill. Or you may be given medication to make your heart work harder if you’re unable to exercise. When your heart is working harder, your heart will be monitored with electrocardiography, echocardiography or other tests.
• Tilt table test. A tilt table test evaluates how your body reacts to changes in position. You’ll lie on a flat table that tilts to raise the upper part of your body, which simulates the movement from a horizontal to standing position. Your blood pressure is taken frequently as the table is tilted.
• Valsalva maneuver. This noninvasive test checks the functioning of your autonomic nervous system by analyzing your heart rate and blood pressure after several cycles of a type of deep breathing: You breathe in deeply and push the air out through your lips, as if you were trying to blow up a stiff balloon.

Treatment of orthostatic hypotension

The goal of treatment for orthostatic hypotension is to restore normal blood pressure. That usually involves increasing blood volume, reducing the pooling of blood in your lower legs and helping blood vessels to push blood throughout your body.

Treatment often addresses the underlying cause — dehydration or heart failure, for example — rather than the low blood pressure itself.

For mild orthostatic hypotension, one of the simplest treatments is to sit or lie down immediately after feeling lightheaded upon standing. Your symptoms should disappear.

When low blood pressure is caused by medications, treatment usually involves changing the dose of the medication or stopping it entirely.

Orthostatic hypotension treatments include:

• Lifestyle changes. Your doctor may suggest several lifestyle changes, including drinking enough water; drinking little to no alcohol; avoiding overheating; elevating the head of your bed; avoiding crossing your legs when sitting; and standing up slowly. If you don’t also have high blood pressure, your doctor might suggest increasing the amount of salt in your diet. If your blood pressure drops after eating, your doctor may recommend small, low-carbohydrate meals.
• Compression stockings. Compression stockings and garments or abdominal binders may help reduce the pooling of blood in your legs and reduce the symptoms of orthostatic hypotension.
• Medications. Several medications, either used alone or together, can be used to treat orthostatic hypotension. For example, the drug fludrocortisone is often used to help increase the amount of fluid in your blood, which raises blood pressure. Midodrine raises standing blood pressure levels by limiting expansion of your blood vessels, which in turn raises blood pressure. Droxidopa (Northera) may be prescribed to treat orthostatic hypotension associated with Parkinson’s disease, multiple system atrophy or pure autonomic failure. Other medications, such as pyridostigmine (Regonol, Mestinon), nonsteroidal anti-inflammatory drugs (NSAIDs), caffeine and epoetin (Epogen, Procrit, others), are sometimes used, too, either alone or with other medications for people who aren’t helped with lifestyle changes or other medications.

Home remedies for orthostatic hypotension

Some simple steps help manage or prevent orthostatic hypotension. Your doctor may give you several suggestions, including:

• Increase salt in your diet. This must be done carefully and only after discussing it with your doctor. Too much salt can cause your blood pressure to increase beyond a healthy level, creating new health risks.
• Eat small meals. If your blood pressure drops after eating, your doctor may recommend small, low-carbohydrate meals.
• Ask about vitamin supplements. Both anemia and vitamin B-12 deficiency can affect blood flow and worsen symptoms of orthostatic hypotension, so iron and vitamin supplements might be helpful for you if you’re deficient.
• Get plenty of fluids. Keeping hydrated helps prevent symptoms of low blood pressure. Drink plenty of water before long periods of standing, or any activities that tend to trigger your symptoms.
• Avoid alcohol. Alcohol can worsen orthostatic hypotension, so limit or avoid it completely.
• Exercise. Regular cardiovascular and strengthening exercises may help reduce symptoms of orthostatic hypotension. Avoid exercising in very hot, humid weather. Stretch and flex your calf muscles before sitting up. If symptoms strike, squeeze your thigh, abdominal and buttock muscles. Squat, march in place or rise onto your tiptoes.
• Avoid bending at the waist. If you drop something on the floor, squat with your knees to recover it.
• Wear waist-high compression stockings. These may help improve blood flow and reduce the symptoms of orthostatic hypotension. Wear them during the day, but take them off for bed and anytime you lie down.
• Get up slowly. You may be able to reduce the dizziness and lightheadedness that occur with orthostatic hypotension by moving slowly from a lying to standing position. Also, when getting out of bed, sit on the edge of your bed for a minute before standing.
• Elevate your head in bed. Sleeping with the head of your bed slightly elevated 15cm (6 inches) can help fight the effects of gravity.
• Move your legs while standing. If you begin to get symptoms while standing, cross your thighs in a scissors fashion and squeeze, or put one foot on a ledge or chair and lean as far forward as possible. These maneuvers encourage blood to flow from your legs to your heart.

Risk factors for low blood pressure

Low blood pressure (hypotension) can occur in anyone, though certain types of low blood pressure are more common depending on your age or other factors:

• Age. Drops in blood pressure on standing or after eating occur primarily in adults older than 65. Neurally mediated hypotension primarily affects children and younger adults.
• Medications. People who take certain medications, for example, high blood pressure medications such as alpha blockers, have a greater risk of low blood pressure.
• Certain diseases. Parkinson’s disease, diabetes and some heart conditions put you at a greater risk of developing low blood pressure.

Complications of low blood pressure

Even moderate forms of low blood pressure can cause dizziness, weakness, fainting and a risk of injury from falls.

And severely low blood pressure can deprive your body of enough oxygen to carry out its normal functions, leading to damage to your heart and brain.

Low blood pressure diagnosis

The goal in testing for low blood pressure is to find the underlying cause. Besides taking your medical history, doing a physical exam and measuring your blood pressure, your doctor might recommend the following:

• Blood tests. These can provide information about your overall health as well as whether you have low blood sugar (hypoglycemia), high blood sugar (hyperglycemia or diabetes) or a low red blood cell count (anemia), all of which can cause lower than normal blood pressure.
• Electrocardiogram (ECG). During this painless, noninvasive test, soft, sticky patches (electrodes) are attached to the skin of your chest, arms and legs. The patches detect your heart’s electrical signals while a machine records them on graph paper or displays them on a screen. An ECG, which can be performed in your doctor’s office, detects irregularities in your heart rhythm, structural abnormalities in your heart, and problems with the supply of blood and oxygen to your heart muscle. It can also tell if you’re having a heart attack or have had one in the past. Heart rhythm abnormalities come and go, and an ECG might not find them. You might be asked to wear a 24-hour Holter monitor to record your heart’s electrical activity as you go about your daily routine.
• Echocardiogram. This noninvasive exam, which includes an ultrasound of your chest, shows detailed images of your heart’s structure and function. Ultrasound waves are transmitted, and their echoes are recorded with a device called a transducer, which is held outside your body. A computer uses the information from the transducer to create moving images on a video monitor.
• Stress test. Some heart problems that can cause low blood pressure are easier to diagnose when your heart is working harder than when it’s at rest. During a stress test, you’ll walk on a treadmill or do some other form of exercise. You might be given medication to make your heart work harder if you’re unable to exercise. When your heart is working harder, your heart will be monitored with electrocardiography or echocardiography. Your blood pressure also may be monitored.
• Valsalva maneuver. This noninvasive test checks the functioning of your autonomic nervous system by analyzing your heart rate and blood pressure after several cycles of a type of deep breathing: You take a deep breath and then force the air out through your lips, as if you’re trying to inflate a balloon.
• Tilt table test. If you have low blood pressure on standing, or from faulty brain signals (neurally mediated hypotension), a tilt table test can evaluate how your body reacts to changes in position. During the test, you lie on a table that’s tilted to raise the upper part of your body, which simulates the movement from horizontal to a standing position.

Low blood pressure treatment

Low blood pressure that either doesn’t cause signs or symptoms or causes only mild symptoms rarely requires treatment.

If you have symptoms, treatment depends on the underlying cause. For instance, when low blood pressure is caused by medications, treatment usually involves changing or stopping the medication or lowering the dose.

If it’s not clear what’s causing low blood pressure or no treatment exists, the goal is to raise your blood pressure and reduce signs and symptoms.

Depending on your age, health and the type of low blood pressure you have, you can do this in several ways:

• Use more salt. Experts usually recommend limiting salt in your diet because sodium can raise blood pressure, sometimes dramatically. For people with low blood pressure, that can be a good thing. But because excess sodium can lead to heart failure, especially in older adults, it’s important to check with your doctor before increasing the salt in your diet.
• Drink more water. Fluids increase blood volume and help prevent dehydration, both of which are important in treating hypotension.
• Wear compression stockings. The elastic stockings commonly used to relieve the pain and swelling of varicose veins can help reduce the pooling of blood in your legs.
• Medications. Several medications can be used to treat low blood pressure that occurs when you stand up (orthostatic hypotension). For example, the drug fludrocortisone, which boosts your blood volume, is often used to treat this form of low blood pressure. Doctors often use the drug midodrine (Orvaten) to raise standing blood pressure levels in people with chronic orthostatic hypotension. It works by restricting the ability of your blood vessels to expand, which raises blood pressure.

Home remedies for your low blood pressure

Depending on the reason for your low blood pressure, you might be able to reduce or prevent symptoms.

• Drink more water, less alcohol. Alcohol is dehydrating and can lower blood pressure, even if you drink in moderation. Water, on the other hand, combats dehydration and increases blood volume.
• Eat a healthy diet. Get all the nutrients you need for good health by focusing on a variety of foods, including whole grains, fruits, vegetables, and lean chicken and fish.
• If your doctor suggests using more salt but you don’t like a lot of salt on your food, try using natural soy sauce or adding dry soup mixes to dips and dressings.
• Raise the head of your bed by about 15cm (6 inches) with bricks or heavy books
• Pay attention to your body positions. Gently move from a prone or squatting to a standing position. Don’t sit with your legs crossed.
• Before arising in the morning, breathe deeply for a few minutes and then slowly sit up before standing. Sleeping with the head of your bed slightly elevated also can help fight the effects of gravity.
• If you begin to get symptoms while standing, cross your thighs in a scissors fashion and squeeze, or put one foot on a ledge or chair and lean as far forward as possible. These maneuvers encourage blood flow from your legs to your heart.
• Eat small, low-carb meals. To help prevent blood pressure from dropping sharply after meals, eat small portions several times a day and limit high-carbohydrate foods such as potatoes, rice, pasta and bread.
• Your doctor also might recommend drinking caffeinated coffee or tea with meals to temporarily raise blood pressure. But because caffeine can cause other problems, check with your doctor before drinking more caffeinated beverages. Also avoid caffeine at nighttime because it can cause insomnia.

1. Jones AE, Kline JA. Shock. In: Marx JA, Hockberger RS, Walls RM, eds. Rosen’s Emergency Medicine: Concepts and Clinical Practice. 8th ed. Philadelphia, PA: Elsevier Saunders; 2014:chap 6[↩]
2. Rivers EP. Approach to the patient with shock. In: Goldman L, Schafer AI, eds. Goldman’s Cecil Medicine. 25th ed. Philadelphia, PA: Elsevier Saunders; 2016:chap 106.[↩]
3. Orthostatic hypotension. https://www.ninds.nih.gov/Disorders/All-Disorders/Orthostatic-Hypotension-Information-Page[↩]