Unless you're a diabetic, low blood sugar isn't risky

The Basics

• Know the Basics about Diabetes
• Diabete's Types, Symptoms
• Do I Have Diabetes
• Managing Your Life
• Diabetes and Pregnancy

Q. How low can your blood sugar level go before it's dangerous?

A. Blood sugar is considered low when it gets below 60. But that's not dangerous for people unless they're diabetic, or have one of a handful of very rare diseases.

For the nondiabetic, low blood sugar is called reactive hypoglycemia, which is not normally dangerous.

''Symptoms can be reversed by giving carbohydrates,'' says Dr. Ronald Goldberg, professor of medicine and head of the University of Miami Diabetes Research Institute.

Diabetics have high blood sugar. Ironically, for those with diabetes, low blood sugar can be life threatening. Some drugs given to stimulate the production of insulin can cause blood sugar to drop to dangerous levels.

''It is a different matter for a nondiabetic,'' says Goldberg.

Low blood sugar (reactive hypoglycemia) isn't dangerous unless the nondiabetic has an uncommon diseases.

One example is insulinoma, a tumor of the insulin-producing cells in the pancreas. It causes more insulin to be produced, which lowers blood sugar.

In this disease, as with diabetics who are reacting to their medication, if the blood sugar drops below 45, the brain shows dysfunction.

Without enough glucose you can get double vision, become confused and even go into convulsions. If the sugar level drops further, coma and death may result. Blood sugar does not get this low from reactive hypoglycemia.

''The brain is absolutely dependent on glucose,'' says Goldberg.

Why people get reactive hypoglycemia is not well understood. Usually it's a temporary condition caused by eating a large meal high in carbohydrates.

That causes an endocrenic reaction in response to the lowered blood sugar. Nerve cells in the brain stimulate adrenalin release. This causes shakiness, sweatiness and tremors. The heart beats hard and the person can become both irritable and hyperaware.

The symptoms can be alleviated by giving the person more carbohydrates, which is precisely what started the whole thing. Goldberg said tests showing this raised some questions that are still unanswered.

In fact, in some studies, people were given large doses of carbohydrates and their blood sugar did not drop below 60.