What is hypoglycemia

Hypoglycemia or hypos, is a condition characterized by an abnormally low level of blood sugar (glucose), usually less than 70 mg/dl [milligrams per deciliter] (3.9 mmol/l)¹. Glucose is your body’s main energy source. However, it is important to talk to your health care provider about your individual blood glucose targets, and what level is too low for you.

The main symptoms associated with hypoglycemia are:

• Sweating
• Fatigue
• Feeling dizzy

Symptoms of hypoglycemia can also include:

• Being pale
• Feeling weak
• Feeling hungry
• A higher heart rate than usual
• Blurred vision
• Confusion
• Convulsions
• Loss of consciousness
• And in extreme cases, coma

The International Study Group ² suggests that a level of 54 mg/dl (<3.0 mmol/l) be defined as denoting serious clinically important hypoglycemia, whether that level is associated with symptoms or not of hypoglycemia.

The International Study Group statement outlines proposed glucose levels to define severe hypoglycemia as:

• Level 1 hypoglycemia: A glucose alert value of 70 mg/dl (3.9 mmol/l) or less. This need not be reported routinely in clinical studies, although this would depend upon the purpose of the study.
• Level 2 hypoglycemia: A glucose level of <54 mg/dl (<3.0 mmol/l) is sufficiently low to indicate serious, clinically important hypoglycemia.
• Level 3 hypoglycemia: Severe hypoglycemia, as defined by the American Diabetes Association, denotes severe cognitive impairment requiring external assistance for recovery.

Hypoglycemia is commonly associated with the treatment of diabetes. However, a variety of conditions, many of them rare, can cause low blood sugar in people without diabetes. Like fever, hypoglycemia isn’t a disease itself — it’s an indicator of a health problem.

Whilst medication is the main factor involved in hypoglycemia within people with diabetes, a number of other factors can increase the risk of hypoglycemia occurring.

Factors linked to a greater risk of hypoglycemia include:

• Too high a dose of medication (insulin or hypoglycemia causing tablets)
• Delayed meals
• Exercise
• Alcohol

The only sure way to know whether you are experiencing hypoglycemia is to check your blood glucose, if possible. Urine tests do not detect hypoglycemia. If you are experiencing symptoms and you are unable to check your blood glucose for any reason, treat the hypoglycemia. Severe hypoglycemia has the potential to cause accidents, injuries, coma, and death.

Hypoglycemic episodes can range from mild to severe.

• Mild hypoglycemia can usually be treated by the individual and are to be expected to some degree in people on insulin. Mild hypos are not associated with significant long term health problems unless they are occurring very regularly or for long periods of time.
• Severe hypoglycemia, however, will require treatment from someone else and may require an ambulance. Severe hypos can lead to immediate danger if not treated immediately. Whilst rare, severe hypos can potentially lead to coma and death. Severe hypoglycemia can be treated with glucagon if a glucagon emergency injection kit is available.

Immediate treatment of hypoglycemia involves quick steps to get your blood sugar level back into a normal range — about 70 to 110 mg/dl, or mg/dL (3.9 to 6.1 millimoles per liter, or mmol/L) — either with high-sugar foods or medications. Long-term treatment requires identifying and treating the underlying cause of hypoglycemia.

• A mild case of hypoglycemia can be treated through eating or drinking 15-20g of fast acting carbohydrate such as glucose tablets, sweets, sugary fizzy drinks or fruit juice. Some people with diabetes may also need to take 15-20g of slower acting carbohydrate if the next meal is not due.
• A blood test should be taken after 15-20 minutes to check whether blood glucose levels have recovered. Severe hypoglycemia may require an ambulance, for example if loss of consciousness occurs or a seizure persists for more than 5 minutes.
• Severe hypoglycemia can be treated with glucagon if a glucagon emergency injection kit is available.

Do symptoms always occur before hypoglycemia?

Most people experience some warnings before the onset of hypoglycemia. However, some diabetics may experience little or no warning before the onset of sudden or severe hypoglycemia. An impaired ability to spot the signs of hypoglycemia is known as loss of hypo awareness (or hypo unawareness).

Who is at risk of hypoglycemia?

Whilst low blood sugar can happen to anyone, dangerously low blood sugar can occur in people who take the following medication:

• Insulin
• Sulphopnylureas (such as glibenclamide, gliclazide, glipizide, glimepiride, tolbutamide)
• Prandial glucose regulators (such as repaglinide, nateglinide)

If you are not sure whether your diabetes medication can cause hypos, read the patient information leaflet that comes with each of your medications or ask your doctor.

It is important to know whether your diabetes medication puts you at risk of hypoglycemia.

What causes hypoglycemia (low blood sugar)

Hypoglycemia occurs when your blood sugar (glucose) level falls too low, below 70 mg/dl (3.9 mmol/l). There are several reasons why this may happen, the most common being a side effect of drugs used for the treatment of diabetes. But to understand how hypoglycemia happens, it helps to know how your body normally regulates blood sugar production, absorption and storage.

Blood sugar regulation

During digestion, your body breaks down carbohydrates from foods — such as bread, rice, pasta, vegetables, fruit and milk products — into various sugar molecules. One of these sugar molecules is glucose, the main energy source for your body. Glucose is absorbed into your bloodstream after you eat, but it can’t enter the cells of most of your tissues without the help of insulin — a hormone secreted by your pancreas.

When the level of glucose in your blood rises, it signals certain cells (beta cells) in your pancreas, located behind your stomach, to release insulin. The insulin, in turn, unlocks your cells so that glucose can enter and provide the fuel your cells need to function properly. Any extra glucose is stored in your liver and muscles in the form of glycogen.

This process lowers the level of glucose in your bloodstream and prevents it from reaching dangerously high levels. As your blood sugar level returns to normal, so does the secretion of insulin from your pancreas.

If you haven’t eaten for several hours and your blood sugar level drops, another hormone from your pancreas called glucagon signals your liver to break down the stored glycogen and release glucose back into your bloodstream. This keeps your blood sugar level within a normal range until you eat again.

Aside from your liver breaking down glycogen into glucose, your body also has the ability to manufacture glucose in a process called gluconeogenesis. This process occurs primarily in your liver, but also in your kidneys, and makes use of various substances that are precursors to glucose.

Possible causes, with diabetes

If you have diabetes, the effects of insulin on your body are drastically diminished, either because your pancreas doesn’t produce enough of it (type 1 diabetes) or because your cells are less responsive to it (type 2 diabetes). As a result, glucose tends to build up in your bloodstream and may reach dangerously high levels. To correct this problem, you likely take insulin or other drugs designed to lower blood sugar levels.

• If you take insulin or some other diabetes medicines, your blood glucose level can drop too low.

If you take too much insulin relative to the amount of glucose in your bloodstream, it can cause your blood sugar level to drop too low, resulting in hypoglycemia. Hypoglycemia may also result if, after taking your diabetes medication, you don’t eat as much as usual (ingesting less glucose) or you exercise more (using up more glucose) than you normally would. Two types of diabetes pills can cause hypoglycemia: sulfonylureas and meglitinides – medicines that help your body make more insulin. To prevent this from happening, it’s likely that your doctor will work with you to find the optimum dosage that fits your regular eating and activity habits.

• Other people may start to have symptoms of hypoglycemia when their blood glucose levels are higher than 70 mg/dl (3.9 mmol/l). This can happen when your blood glucose levels are very high and start to go down quickly. If this is happening, discuss treatment with your health care provider.

The following factors can make hypoglycemia more likely:

• Not eating enough carbohydrates (carbs)

When you eat foods containing carbohydrates, your digestive system breaks down the sugars and starches into glucose. Glucose then enters your bloodstream and raises your blood glucose level. If you don’t eat enough carbohydrates to match your medication, your blood glucose could drop too low.

• Skipping or delaying a meal

If you skip or delay a meal, your blood glucose could drop too low. Hypoglycemia also can occur when you are asleep and haven’t eaten for several hours.

• Increasing physical activity

Increasing your physical activity level beyond your normal routine can lower your blood glucose level for up to 24 hours after the activity.

• Drinking too much alcohol without enough food

Alcohol makes it harder for your body to keep your blood glucose level steady, especially if you haven’t eaten in a while. The effects of alcohol can also keep you from feeling the symptoms of hypoglycemia, which may lead to severe hypoglycemia.

• Being sick

When you’re sick, you may not be able to eat as much or keep food down, which can cause low blood glucose. Learn more about taking care of your diabetes when you’re sick.

Possible causes, without diabetes

Hypoglycemia in people without diabetes is much less common. Causes may include the following:

• Medications. Taking someone else’s oral diabetes medication accidentally is a possible cause of hypoglycemia. Other medications may cause hypoglycemia, especially in children or in people with kidney failure. One example is quinine (Qualaquin), which is used to treat malaria.
• Excessive alcohol consumption. Drinking heavily without eating can block your liver from releasing stored glucose into your bloodstream, causing hypoglycemia.
• Some critical illnesses. Severe illnesses of the liver, such as severe hepatitis, can cause hypoglycemia. Disorders of the kidney, which can keep your body from properly excreting medications, can affect glucose levels due to a buildup of those medications. Long-term starvation, as may occur in the eating disorder anorexia nervosa, can result in the depletion of substances your body needs in gluconeogenesis, causing hypoglycemia.
• Insulin overproduction. A rare tumor of the pancreas (insulinoma) may cause overproduction of insulin, resulting in hypoglycemia. Other tumors may result in excessive production of insulin-like substances. Enlargement of beta cells of the pancreas that produce insulin (nesidioblastosis) may result in excessive insulin release, causing hypoglycemia.
• Hormone deficiencies. Certain disorders of the adrenal glands and the pituitary gland can result in a deficiency of key hormones that regulate glucose production. Children with these disorders are more prone to hypoglycemia than are adults.

Hypoglycemia after meals

Hypoglycemia usually occurs when you haven’t eaten (when you’re in a fasting state), but that’s not always the case. Sometimes hypoglycemia occurs after meals because the body produces more insulin than is needed.

This type of hypoglycemia, called reactive or postprandial hypoglycemia, may occur in people who have had stomach surgery. It may also occur in people who haven’t had this surgery.

Complications of hypoglycemia

If you ignore the symptoms of hypoglycemia too long, you may lose consciousness. That’s because your brain needs glucose to function properly.

Recognize the signs and symptoms of hypoglycemia early because untreated hypoglycemia can lead to:

• Seizure
• Loss of consciousness
• Death

Hypoglycemia unawareness

Over time, repeated episodes of hypoglycemia can lead to hypoglycemia unawareness. The body and brain no longer produce signs and symptoms that warn of a low blood sugar, such as shakiness or irregular heartbeats. When this happens, the risk of severe, life-threatening hypoglycemia is increased.

People with hypoglycemia unawareness are also less likely to be awakened from sleep when hypoglycemia occurs at night.

Hypoglycemia unawareness occurs more frequently in those who:

• frequently have low blood glucose episodes (which can cause you to stop sensing the early warning signs of hypoglycemia)
• have had diabetes for a long time
• tightly control their diabetes (which increases your chances of having low blood glucose reactions)

If you think you have hypoglycemia unawareness, speak with your health care provider. Your health care provider may adjust/raise your blood glucose targets to avoid further hypoglycemia and risk of future episodes.

Undertreated diabetes

If you have diabetes, episodes of low blood sugar are uncomfortable and can be frightening. Repeated episodes of hypoglycemia may cause you to take less insulin to ensure that your blood sugar level doesn’t go too low. But long-term high blood sugar levels can be dangerous, too, possibly causing damage to your nerves, blood vessels and various organs.

Prevention of hypoglycemia

How to prevent hypoglycemia if you have diabetes

If you are taking insulin, a sulfonylurea, or a meglitinide, using your diabetes management plan and working with your health care team to adjust your plan as needed can help you prevent hypoglycemia. The following actions can also help prevent hypoglycemia:

Check blood glucose levels

Knowing your blood glucose level can help you decide how much medicine to take, what food to eat, and how physically active to be. To find out your blood glucose level, check yourself with a blood glucose meter as often as your doctor advises.

Hypoglycemia unawareness

Sometimes people with diabetes don’t feel or recognize the symptoms of hypoglycemia, a problem called hypoglycemia unawareness. If you have had hypoglycemia without feeling any symptoms, you may need to check your blood glucose more often so you know when you need to treat your hypoglycemia or take steps to prevent it. Be sure to check your blood glucose before you drive.

If you have hypoglycemia unawareness or have hypoglycemia often, ask your health care provider about a continuous glucose monitor. A continuous glucose monitor checks your blood glucose level at regular times throughout the day and night. Continuous glucose monitoring can tell you if your blood glucose is falling quickly and sound an alarm if your blood glucose falls too low. Continuous glucose monitor alarms can wake you up if you have hypoglycemia during sleep.

Eat regular meals and snacks

Your meal plan is key to preventing hypoglycemia. Eat regular meals and snacks with the correct amount of carbohydrates to help keep your blood glucose level from going too low. Also, if you drink alcoholic beverages, it’s best to eat some food at the same time.

Be physically active safely

Physical activity can lower your blood glucose during the activity and for hours afterward. To help prevent hypoglycemia, you may need to check your blood glucose before, during, and after physical activity and adjust your medicine or carbohydrate intake. For example, you might eat a snack before being physically active or decrease your insulin dose as directed by your health care provider to keep your blood glucose from dropping too low.

Work with your health care team

Tell your health care team if you have had hypoglycemia. Your health care team may adjust your diabetes medicines or other aspects of your management plan. Learn about balancing your medicines, eating plan, and physical activity to prevent hypoglycemia. Ask if you should have a glucagon emergency kit to carry with you at all times.

Be sure to always have a fast-acting carbohydrate with you, such as juice or glucose tablets, so you can treat a falling blood sugar before it dips dangerously low.

Medical IDs

Many people with diabetes, particularly those who use insulin, should have a medical ID with them at all times.

In the event of a severe hypoglycemic episode, a car accident, or other emergency, the medical ID can provide critical information about the person’s health status, such as the fact that they have diabetes, whether or not they use insulin, whether they have any allergies, etc. Emergency medical personnel are trained to look for a medical ID when they are caring for someone who can’t speak for themselves.

Medical IDs are usually worn as a bracelet or a necklace. Traditional IDs are etched with basic, key health information about the person, and some IDs now include compact USB drives that can carry a person’s full medical record for use in an emergency.

How to prevent hypoglycemia if you don’t diabetes

If you don’t have diabetes but have recurring episodes of hypoglycemia, eating frequent small meals throughout the day is a stopgap measure to help prevent your blood sugar levels from getting too low. However, this approach isn’t an advisable long-term strategy. Work with your doctor to identity and treat the underlying cause of hypoglycemia.

Signs and symptoms of hypoglycemia

Hypoglycemic symptoms are important clues that you have low blood glucose. Each person’s reaction to hypoglycemia is different, so it’s important that you learn your own signs and symptoms when your blood glucose is low.

Similar to the way a car needs gas to run, your body and brain need a constant supply of sugar (glucose) to function properly. If glucose levels become too low, as occurs with hypoglycemia, it can happen quickly and cause these signs and symptoms:

• Shakiness
• Nervousness or anxiety
• Heart palpitations
• Fatigue
• Pale skin
• Crying out during sleep
• Sweating, chills and clamminess
• Irritability or impatience
• Argumentative or combative
• Confusion, including delirium
• Rapid/fast heartbeat
• Lightheadedness or dizziness
• Hunger and nausea
• Sleepiness
• Blurred/impaired vision
• Tingling or numbness in the lips or tongue
• Headaches
• Weakness or fatigue
• Anger, stubbornness, or sadness
• Lack of coordination
• Nightmares or crying out during sleep

Some symptoms of hypoglycemia during sleep are:

• crying out or having nightmares
• sweating enough to make your pajamas or sheets damp
• feeling tired, irritable, or confused after waking up

As hypoglycemia worsens, signs and symptoms may include:

• Confusion, abnormal behavior or both, such as the inability to complete routine tasks
• Visual disturbances, such as blurred vision
• Seizures
• Loss of consciousness
• If left untreated it may cause death

People with severe hypoglycemia may appear as if they’re intoxicated. They may slur their words and move clumsily.

Many conditions other than hypoglycemia may cause these signs and symptoms. A blood sample to test your blood sugar level at the time of these signs and symptoms is how to know for sure that hypoglycemia is the cause.

Hypoglycemia Diagnosis

Your doctor will use three criteria — often referred to as Whipple’s triad — to diagnose hypoglycemia. Whipple’s triad includes the following factors:

1. Signs and symptoms of hypoglycemia. You may not exhibit signs and symptoms of hypoglycemia during your initial visit with your doctor. In this case, your doctor may have you fast overnight (or for a longer period). This will allow hypoglycemic symptoms to occur so that he or she can make a diagnosis. It’s also possible that you’ll need to undergo an extended fast in a hospital setting. Or if your symptoms occur after a meal, your doctor will want to test your glucose levels after a meal.
2. Documentation of low blood glucose when the signs and symptoms occur. Your doctor will draw a sample of your blood to be analyzed in the laboratory.
3. Disappearance of the signs and symptoms. The third part of the diagnostic triad involves whether your signs and symptoms go away when blood glucose levels are raised.

In addition, your doctor will likely conduct a physical examination and review your medical history.

Hypoglycemia treatment

If you begin to feel one or more hypoglycemia symptoms, check your blood glucose. If your blood glucose level is below your target or less than 70 mg/dl (3.9 mmol/l), eat or drink 15 grams of carbohydrates right away. Treatment of hypoglycemia involves quick steps to get your blood sugar level back into a normal range — about 70 to 110 mg/dl, or mg/dL (3.9 to 6.1 millimoles per liter, or mmol/L).

Treatment of hypoglycemia

• Consume 15-20 grams of glucose or simple carbohydrates
• Recheck your blood glucose after 15 minutes
• If hypoglycemia continues, repeat.
• Once blood glucose returns to normal, eat a small snack if your next planned meal or snack is more than an hour or two away.

15 grams of simple carbohydrates commonly used:

• glucose tablets (follow package instructions)
• gel tube (follow package instructions)
• 2 tablespoons of raisins
• 4 ounces (1/2 cup) of juice or regular soda (not diet)
• 1 tablespoon sugar, honey, or corn syrup
• 8 ounces of nonfat or 1% milk
• hard candies, jellybeans, or gumdrops (see package to determine how many to consume)

Wait 15 minutes and check your blood glucose again. If your glucose level is still low, eat or drink another 15 grams of glucose or carbohydrates. Check your blood glucose again after another 15 minutes. Repeat these steps until your glucose level is back to normal.

If your next meal is more than 1 hour away, have a snack to keep your blood glucose level in your target range. Try crackers or a piece of fruit.

• *People who have kidney disease shouldn’t drink orange juice for their 15 grams of carbohydrates because it contains a lot of potassium. Apple, grape, or cranberry juice are good options.

If your symptoms are more severe, impairing your ability to take sugar by mouth, you may need an injection of glucagon or intravenous glucose. Do not give food or drink to someone who is unconscious, as he or she may aspirate these substances into the lungs.

If you’re prone to severe episodes of hypoglycemia, ask your doctor if a home glucagon kit might be appropriate for you. In general, people with diabetes who are treated with insulin should have a glucagon kit for low blood sugar emergencies. Family and friends need to know where to find the kit, and need to be taught how to use it before an emergency occurs.

Treating hypoglycemia if you take acarbose or miglitol

If you take acarbose or miglitol along with diabetes medicines that can cause hypoglycemia, you will need to take glucose tablets or glucose gel if your blood glucose level is too low. Eating or drinking other sources of carbohydrates won’t raise your blood glucose level quickly enough.

What if I have severe hypoglycemia and can’t treat myself?

Someone will need to give you a glucagon injection if you have severe hypoglycemia. An injection of glucagon will quickly raise your blood glucose level. Talk with your health care provider about when and how to use a glucagon emergency kit. If you have an emergency kit, check the date on the package to make sure it hasn’t expired.

If you are likely to have severe hypoglycemia, teach your family, friends, and coworkers when and how to give you a glucagon injection. Also, tell your family, friends, and coworkers to call your local emergency number right away after giving you a glucagon injection or if you don’t have a glucagon emergency kit with you.

If you have hypoglycemia often or have had severe hypoglycemia, you should wear a medical alert bracelet or pendant. A medical alert ID tells other people that you have diabetes and need care right away. Getting prompt care can help prevent the serious problems that hypoglycemia can cause.

Glucagon

If left untreated, hypoglycemia may lead to a seizure or unconsciousness (passing out, a coma). In this case, someone else must take over.

Glucagon is a hormone that stimulates your liver to release stored glucose into your bloodstream when your blood glucose levels are too low. Injectable glucagon kits are used as a medication to treat someone with diabetes that has become unconscious from a severe insulin reaction. Glucagon kits are available by prescription. Speak with your health care provider about whether you should buy one, and how and when to use it.

The people you are in frequent contact with (for example, family members, significant others, and coworkers) should also be instructed on how to administer glucagon to treat severe hypoglycemic events. Have them call your local emergency number if they feel they can’t handle the situation (for example, if the hypoglycemic person passes out, does not regain consciousness, or has a seizure, if the care taker does not know how to inject glucagon, or if glucagon is not available).

If glucagon is needed:

• Inject glucagon into the individual’s buttock, arm or thigh, following the manufacturer’s instructions.
• When the individual regains consciousness (usually in 5-15 minutes), they may experience nausea and vomiting.
• If you have needed glucagon, let your health care provider know, so they can discuss ways to prevent severe hypoglycemia in the future.

Do NOT:

• Inject insulin (will lower blood glucose even more)
• Provide food or fluids (individual can choke)
• Put hands in mouth (individual can choke)

Treatment of the underlying condition

Preventing recurrent hypoglycemia requires your doctor to identify the underlying condition and treat it. Depending on the underlying cause, treatment may involve:

• Medications. If a medication is the cause of your hypoglycemia, your doctor will likely suggest changing the medication or adjusting the dosage.
• Tumor treatment. A tumor in your pancreas is treated by surgical removal of the tumor. In some cases, partial removal of the pancreas is necessary.

1. Hypoglycemia (Low Blood Glucose). http://www.diabetes.org/living-with-diabetes/treatment-and-care/blood-glucose-control/hypoglycemia-low-blood.html[↩]
2. Glucose Concentrations of Less Than 3.0 mmol/L (54 mg/dL) Should Be Reported in Clinical Trials: A Joint Position Statement of the American Diabetes Association and the European Association for the Study of Diabetes. International Hypoglycaemia Study Group. Diabetes Care Jan 2017, 40 (1) 155-157; DOI: 10.2337/dc16-2215 http://care.diabetesjournals.org/content/40/1/155[↩]