Overview

Glucose a form of sugar is an important fuel for your body. Carbohydrates are the main dietary sources of glucose. After a meal glucose molecules are absorbed into your bloodstream and carried to the cells where they are used for energy. Insulin a hormone produced by your pancreas helps glucose enter cells. If you take in more glucose than your body needs at the time your body stores the extra glucose in your liver and muscles in a form called glycogen. Your body can use the stored glucose whenever it is needed for energy between meals. Extra glucose can also be converted to fat and stored in fat cells.

When blood glucose begins to fall glucagon another hormone produced by the pancreas signals the liver to break down glycogen and release glucose causing blood glucose levels to rise toward a normal level. If you have diabetes this glucagon response to hypoglycemia may be impaired making it harder for your glucose levels to return to the normal range.

In people taking certain blood-glucose lowering medications blood glucose can fall too low for a number of reasons:

• meals or snacks that are too small delayed or skipped
• excessive doses of insulin or some other diabetes drugs especially sulfonylureas and meglitinides
• increased activity or exercise
• excessive drinking of alcohol

• hunger
• nervousness and shakiness
• perspiration
• dizziness or light-headedness
• sleepiness
• confusion
• difficulty speaking
• feeling anxious or weak

Hypoglycemia can also happen while people with diabetes are sleeping. This can occur with use of insulin. You might:

• cry out or have nightmares
• find that your pajamas or sheets are damp from perspiration
• feel tired be in a low mood irritable or confused when you wake up

Symptoms of hypoglycemia can vary from person to person. Document your blood sugar readings and get to know your own signs and describe them to your friends and family so they will be able to help you. If your child has diabetes tell school staff about hypoglycemia and how to treat it.

If you experience hypoglycemia several times a week call your doctor. You may need a change in your treatment plan: less medication or a different medication a new schedule for your insulin shots or medication a different meal plan or a new exercise plan.

Treatment

If you think your blood glucose is below normal (see chart below) use a blood glucose meter to check your level. If it is low or if you can't check it have one of these "quick fix" foods right away to raise your blood glucose:

• 2 or 3 glucose tablets
• 1/2 cup (4 ounces) of any fruit juice
• 1/2 cup (4 ounces) of a regular (not diet) soft drink
• 1 cup (8 ounces) of milk
• 5 or 6 pieces of hard candy
• 1 or 2 teaspoons of sugar or honey

After 15 minutes check your blood glucose again. If it is still too low have another serving. Repeat these steps until your blood glucose returns to normal. Then if it will be an hour or more before your next meal have a snack.

If you take insulin or a diabetes medication that can cause hypoglycemia always carry one of the quick-fix foods with you. Wearing a medical identification bracelet or necklace is also a good idea.

Ideal Blood Glucose Levels

Severe hypoglycemia can cause you to lose consciousness. In these extreme cases when you lose consciousness and cannot eat glucagon can be injected to quickly raise your blood glucose level. Ask your health care provider if having a glucagon kit at home and at work is appropriate for you. This is particularly important if you have type 1 diabetes. Your family friends and co-workers will need to be taught how to give you a glucagon injection in an emergency.

Your diabetes treatment plan is designed to match your medication dosage and schedule to your usual meals and activities. If you take insulin but then skip a meal the insulin will still lower your blood glucose but it will not find the food it is designed to break down. This mismatch might result in hypoglycemia.

To help prevent hypoglycemia you should keep the following in mind:

• Your diabetes medications. Some medications can cause hypoglycemia. Ask your health care provider if yours can. Also always take medications and insulin in the recommended doses and at the recommended times.
• Your meal plan. Meet with a registered dietitian and agree on a meal plan that fits your preferences and lifestyle. Do your best to follow this meal plan most of the time. Eat regular meals have enough food at each meal and try not to skip meals or snacks. If you do skip meals for example if you have a bad stomach flu (gastroenteritis) it may be wise to adjust your medications especially if you are insulin dependent.
• Your daily activity. Talk to your health care team about whether you should have a snack or adjust your medication before sports or exercise. If you know that you will be more active than usual or will be doing something that is not part of your normal routine·shoveling snow for example·consider having a snack first.
• Alcoholic beverages. Drinking especially on an empty stomach can cause hypoglycemia even a day or two later. If you drink an alcoholic beverage always have a snack or meal at the same time. As well too many alcoholic beverages tends to limit self-care decision-making skills.
• Your diabetes management plan. Intensive diabetes management·keeping your blood glucose as close to the normal range as possible to prevent long-term complications·can increase the risk of hypoglycemia. If your goal is tight control talk to your health care team about ways to prevent hypoglycemia and how best to treat it if it does occur.

Prevention of hypoglycemia while you are driving a vehicle or operating machinery is especially important. Checking blood glucose frequently and snacking as needed to keep your blood glucose within normal range (above 5 mmol/L) will help prevent accidents.

Other Types of Hypoglycemia

Two types of hypoglycemia can occur in people who do not have diabetes: reactive (postprandial or after meals) and fasting (postabsorptive). Reactive hypoglycemia is not usually related to any underlying disease; fasting hypoglycemia often is.

Symptoms of both types resemble the symptoms that people with diabetes and hypoglycemia experience: hunger nervousness perspiration shakiness dizziness light-headedness sleepiness confusion difficulty speaking and feeling anxious or weak.

If you are diagnosed with hypoglycemia your doctor will try to find the cause by using laboratory tests to measure blood glucose insulin and other chemicals that play a part in the body's use of energy.

In reactive hypoglycemia symptoms appear within 4 hours after you eat a meal.

• ask you about signs and symptoms
• test your blood glucose while you are having symptoms (The doctor will take a blood sample from your arm and send it to a laboratory for analysis. A personal blood glucose monitor cannot be used to diagnose reactive hypoglycemia.)
• check to see whether your symptoms ease after your blood glucose returns to 70 or above (after eating or drinking)

A blood glucose level that is less than 4 mmol/L at the time of symptoms and subsequent relief after eating will confirm the diagnosis.

The oral glucose tolerance test is no longer used to diagnose hypoglycemia; experts now know that the test can actually trigger hypoglycemic symptoms.

The causes of most cases of reactive hypoglycemia are still open to debate. Some researchers suggest that certain people may be more sensitive to the body's normal release of the hormone epinephrine which causes many of the symptoms of hypoglycemia. Others believe that deficiencies in glucagon secretion might lead to hypoglycemia.

A few causes of reactive hypoglycemia are certain but they are uncommon. Gastric (stomach) surgery for instance can cause hypoglycemia because of the rapid passage of food into the small intestine. Also rare enzyme deficiencies diagnosed early in life such as hereditary fructose intolerance may cause reactive hypoglycemia.

To relieve reactive hypoglycemia some health professionals recommend taking the following steps:

• eat small meals and snacks about every 3 hours
• exercise regularly
• eat a variety of foods including meat poultry fish or non-meat sources of protein; starchy foods such as whole-grain bread rice and potatoes; fruits; vegetables; and dairy products
• choose high-fibre foods
• avoid or limit foods high in sugar especially on an empty stomach

Your doctor can refer you to a registered dietitian for personalized meal planning advice. Although some health professionals recommend a diet high in protein and low in carbohydrates studies have not proven the effectiveness of this kind of diet for reactive hypoglycemia.

Fasting hypoglycemia is diagnosed from a blood sample that shows a blood glucose level of less than 3 mmol/L after an overnight fast between meals or after exercise.

• salicylates including aspirin when taken in large doses
• sulfa medicines which are used to treat infections
• pentamidine which treats a very serious kind of pneumonia
• quinine which is used to treat malaria

If using any of these medications causes your blood glucose to drop your doctor may advise you to stop using the drug or change the dosage.

Children rarely develop hypoglycemia. If they do causes may include

• Brief intolerance to fasting often in conjunction with an illness that disturbs regular eating patterns. Children usually outgrow this tendency by age 10.
• Hyperinsulinism which is the excessive production of insulin. This condition can result in transient neonatal hypoglycemia which is common in infants of mothers with diabetes. Persistent hyperinsulinism in infants or children is a complex disorder that requires prompt evaluation and treatment by a specialist.
• Enzyme deficiencies that affect carbohydrate metabolism. These deficiencies can interfere with the body's ability to process natural sugars such as fructose and galactose glycogen or other metabolites.
• Hormonal deficiencies such as lack of pituitary or adrenal hormones.