Hypoglycemia (Low Blood Sugar) Symptoms and Diabetes

Medical Author: Ruchi Mathur, M.D.
Medical Editor: William C. Shiel, Jr., MD, FACP, FACR

I am fortunate to have a team of great nurses and a wonderful nutritionist in my office. As I was on my way into see a patient, I overheard one of our nurses going into great deal of detail educating a young patient with diabetes about the concerns of low blood sugar. Her conversation reminded me that this is a subject of great importance to patients with diabetes. I will take this opportunity to highlight information on issues related to hypoglycemia (low blood sugar) such as:

  • What are the signs and symptoms of hypoglycemia?
  • When should you be concerned?
  • What to do for diabetes treatment?
  • When you should seek medical attention.

Despite significant advances in diabetes treatment, hypoglycemia (low blood sugar or glucose) is still a common problem among patients who are trying to achieve better control of their blood sugar. Medical research has found that low blood sugar occurred more commonly in patients who adhered to a strict control of their blood sugar. While this approach affords them better outcomes for complications such as eye disease, kidney disease, and nerve damage, these patients also endured more episodes of low blood sugar (hypoglycemia).

Hypoglycemia is the result of excess insulin in the blood, which causes excessively low blood sugar levels. While symptoms vary from person to person and range in severity, there are a few common complaints when the blood sugar is too low. The symptoms are caused by the nervous system's response to the stress of having low levels of circulating blood sugar.

The symptoms usually occur gradually and may be associated with warning signs such as:

If these signs are ignored, and blood sugar levels continue to fall, more severe symptoms may occur, such as confusion, behavior changes, stupor, and unconsciousness. These later symptoms are the result of a reduction in fuel source to the brain. Eventually, a patient can develop a seizure and coma may ensure. While most patients have never experienced such severe symptoms, those who have recurrent, severe episodes may suffer from long-term brain damage.

Hypoglycemia can occur rarely in patients without diabetes. These causes are beyond the scope of this discussion. In patients with diabetes, hypoglycemia is uncommon in those who are treated solely with lifestyle modifications. This means that the condition is typically caused by over-medicating. There is an admonition, though, in some patients with type 2 diabetes (who, by definition, have high circulating levels of insulin), a decrease in carbohydrate intake or problems with digesting foods may cause a mismatch in insulin, thereby leading to symptoms of hypoglycemia. Hypoglycemia is also rare in patients treated with certain drugs such as acarbose (Precose), metformin (Glucophage), rosiglitazone (Avandia), and pioglitazone (Actos). However, when these medicines are used in combination with drugs such as glyburide (Micronase, Diabeta, Glynase), or other drugs in the family of sulfonylurea and meglitinides [repaglinide (Prandin), nateglinide (Starlix)], hypoglycemia may occur. Hypoglycemia may also occur when sulfonylurea agents or meglitinides are used on their own, with the risk being higher in sulfonylurea agents.

Most patients recognize the early warning signs of hypoglycemia and counteract them by eating. Ideally, a simple sugar that is easily absorbed (such as a pack of table sugar, glucose tablets, lifesavers, juice, or regular soda) should be eaten. While chocolate seems an appealing choice, as perhaps does cake and other sweets, these take far too long to be absorbed and are thus not ideal choices. Half a glass of juice or soda should work adequately and care should be taken not to over treat so that blood sugars do not rise excessively. If possible, the blood sugar level should be checked before and then again at about 20 minutes after treating. If a reading in the 70's or less is obtained, treatment by eating or drinking a simple sugar is appropriate. It is also important to remember that once the blood sugar reaches a safe level, it needs to stay there. At this point it is recommended to take a longer acting carbohydrate (a slice of bread, for example) to sustain the blood sugar level.