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What Can I Do To Prevent Serious Hypoglycemic Episodes When I am Hypoglycemic Unaware?

Low blood glucose or hypoglycemia is one of the most common problems associated with diabetes, in particular, insulin treatment.

Hypoglycemia is defined as a blood glucose level below 70 mg/dl if your meter tests whole blood. However, most new meters these days test plasma glucose, so you should consider yourself as having low blood glucose if your level is 80 mg/dl or lower, or if your level is 90 mg/dl or lower and you have symptoms. (Check your instruction book or contact your meter manufacturer if you are unsure which type of meter you are using.) Hypoglycemia is usually unpleasant, with the most common symptoms including feeling shaky, sweaty, and having one's heart pound. The most common reasons for hypoglycemia are too much insulin, too little food, or too much activity. Most hypoglycemia is mild with recognizable symptoms, and if quickly and appropriately treated it is more of an inconvenience than a cause for alarm.

Severe hypoglycemia, however, is defined as the point when you are not able to independently treat yourself. The most common reasons for severe hypoglycemia are not recognizing symptoms or waiting to treat symptoms. We know that the traditional physical and emotional symptoms of a low blood glucose may begin to fade away after 5 years with diabetes. In fact, after 20 or more years with diabetes it is not unusual for these symptoms to become too subtle to recognize or happen only after being too low to react to them. This condition is called hypoglycemic unawareness. Experts think it may be due to nerve damage (neuropathy), which dampens the release of adrenaline — the hormone that triggers the common symptoms.

Even though you may lose the physical and mood symptoms associated with low blood glucose, you do not lose the mental (neuroglycopenic) symptoms of low blood glucose. Over time, these mental symptoms may become your best and first symptoms of low blood sugar. Examples of mild hypoglycemic mental symptoms include difficulty concentrating, slowed speech, slowed thinking, or lack of coordination. These kinds of symptoms become critically important because they start at a blood glucose level where you should still be able to independently treat yourself. These early mental symptoms are subtle and have to be distinguished from normal performance; for example, most people are slower at math when their blood glucose is low, but if you are just as good at math when your blood glucose is low as when they are normal, then doing math tells you very little. Feeling confused and disoriented are certainly mental symptoms, but once you are having these kinds of symptoms it is too late for an independent response.

Mental symptoms can help you detect early mild hypoglycemia, but research indicates that they are much more effective if used in combination with a sophisticated understanding of the match between insulin action, carbohydrates and activity. In essence, you use these factors to predict the times of the day when you might be at higher risk for hypoglycemia and therefore pay closer attention to early warning signs at those times. Of course, when you are asleep, symptom detection doesn't help. The goal when you are asleep is to prevent hypoglycemia by predicting hypoglycemia and then taking corrective action. In this case, symptoms are not useful and prevention is based upon an accurate understanding of the insulin-food-activity match.

Most people have mental symptoms that give them early warning of hypoglycemia. Research tells us the most common reasons that people progress from mild or moderate hypoglycemia to severe hypoglycemia is because they (1) recognize symptoms and wait to treat (2) rationalize symptoms away or (3) have not considered subtle, personal, or idiosyncratic symptoms as an indication of hypoglycemia.

Page last updated: July 29, 2014