Spotting the signs of hypoglycemia

Hypoglycemia, or low blood sugar, is a dreaded complication of diabetes.  If you have diabetes, you know just how lousy you feel when your blood sugar gets too low.  This is a potential problem for anyone who takes insulin or several other glucose-lowering medications, including sulfonylureas or glinides, either alone or in combination with other antidiabetic drugs. Hypoglycemia can be caused by too much insulin, too much exercise, too little food or carbohydrates, a missed or delayed meal, or a combination of these factors. As you work aggressively to get your blood sugar levels near normal, your risk for hypoglycemia increases.

If you have diabetes, it's important for you and your loved ones (and even friends and co-workers) to recognize and understand hypoglycemia so it can be prevented and treated before it becomes a life-threatening crisis.

Low blood sugar usually sets off alarms in many organ systems. The brain, which relies on glucose to function, is especially sensitive to sugar deprivation. The first signs of hypoglycemia resemble those of an anxiety attack because a decline in blood sugar affects the autonomic nervous system. Epinephrine (also known as adrenaline) is secreted, causing:

• sweating
• nervousness
• trembling
• palpitations
• lightheadedness
• often hunger.

The release of epinephrine is a corrective response to hypoglycemia not only because it will signal you to eat, but because it stimulates your liver to make more sugar.

More profound levels of hypoglycemia affect brain function and result in:

• blurred vision
• slurred speech
• confusion
• other behavior that resembles inebriation, such as belligerence or silliness.

A further drop in blood sugar levels or failure to treat the condition promptly may result in:

• oss of consciousness
• seizures
• death

Not everyone experiences all these symptoms, and it can be hard to tell the difference between hypoglycemia and anxiety over a problem at work or an argument with your spouse. In addition, beta blockers (used to treat high blood pressure and heart disease) and alcohol can exacerbate hypoglycemia by masking early symptoms. Therefore, they must be used cautiously.

If hypoglycemia occurs during sleep, the only clues may be damp pajamas (from sweating), vivid nightmares, or a nagging headache on awakening. It's important to be attuned to these early signs and to know what blood sugar levels set off hypoglycemia.

While it's a good idea to test your blood glucose level if you suspect you're having a hypoglycemic reaction, often there just isn't time. Once you start to feel strange, don't put off treatment. You need to eat or drink some sugar that will reach your bloodstream quickly. If you can't check your blood sugar at the time symptoms begin, don't wait to treat. Treat first and check later.

About 10 to 15 grams of carbohydrate should suffice. That can be 4 to 6 ounces of fruit juice, half a can of regular soda, 2 tablespoons of raisins, or some candy (usually five to seven LifeSavers or six jellybeans will be enough). A glass of milk also works well, as do fast-acting glucose tablets, which are sold at pharmacies. You can expect relief 10 to 15 minutes after eating the sugar. But test your blood glucose level at that time, and if it's still low, you may need to repeat the treatment.

Doctors strongly suggest that people taking insulin carry some hard candy, sugar lumps, or even a tube of cake icing so they're ready to treat themselves at the first signs of hypoglycemia. However, hypoglycemic reaction shouldn't be seen as a justification for pigging out on sweets. It's crucial to get enough glucose to correct the problem, but it's not wise to overload, which will only cause your blood sugar levels to surge later.

Have you experienced hypoglycemia? What symptoms did you get? How quickly did you treat it—and how?

Julie K. Silver, M.D., is an assistant professor in the Department of Physical Medicine and Rehabilitation at Harvard Medical School. She is also the Chief Editor of Books for Harvard Health Publications. 

Diabetes

Nearly 21 million Americans suffer from diabetes, and as anyone who has been affected by the disorder knows, it is about much more than a statistic: it means a new way of life. Diabetes: A plan for livingis a special report from Harvard Medical School that will help you learn how to better understand and manage your diabetes, including type 1 and type 2, as well as other variations of the disease. This report will show you that it's not just possible to live with diabetes; it's possible to live well.

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