What is hypoglycemia unawareness?

Hypoglycemia unawareness is when you lose consciousness without ever knowing your blood glucose levels were dropping or that you were showing other symptoms of hypoglycemia. It tends to happen to people who have had diabetes for many years, but it doesn't happen to everyone. It is more likely in people who have neuropathy (nerve damage), people on tight glucose control, and people who take certain heart or high blood pressure medicines.

This is an important issue for people with diabetes. Hypoglycemia means low blood sugar. It is the opposite of hyperglycemia, which means elevated blood sugar. Since diabetes is usually associated with high blood sugar, it may come as a surprise to know that low blood sugar is much more common in diabetics and is the most common problem they have in managing their diabetes. Hypoglycemia, or low blood sugar, is typically due to medication – typically insulin or the sulfonylurea class drugs (glyburide, glipizide and related drugs). A common scenario is that a person will be given a certain dose of insulin or (let's say) glyburide, and all will be fine for a few days. Then he or she might get an upset stomach and skip a meal, or be late for a train and have to run vigorously for 10 minutes, or start taking a new nutritional supplement with chromium – something very different from the usual daily routine. This can then result in hypoglycemia because his or her sugar intake is much lower or the action of insulin is potentiated. Low blood sugar can result. Usually, a person knows this because he begins to feel irritable, very hungry, shaky, and drowsy. He may even begin to slur his words and appear to be intoxicated. These are all signals that the blood sugar is too low and needs to be treated immediately with sugar, orange juice, a dextrose tablet, or a glucagon injection. These are all methods used by diabetics to treat hypoglycemia and are important for them to know.

Hypogylcemia unawareness refers to a subgroup of people with diabetes who cannot tell that their blood sugar is low. They often do not feel any symptoms until their blood sugar is so low that they may actually pass out. This is often referred to as "defective warning system" and is sometimes related to diabetic nerve damage. Regular blood sugar testing and monitoring is essential for people in this situation.

Hypoglycemia is fancy medical word for low blood sugar. Under normal circumstances, if your blood sugar drops you’d feel a range of warning signs. This is your body’s way of alerting you of some serious trouble ahead.

The warning signs of low blood sugar vary from person to person, but some common ones are the sensation of being in an elevator that the cables just broke, breaking out in a sweat (especially around the face), and suffering from quivering hands. You might also get dizzy and feel your heart pounding in your chest.

All of this matters because your brain is a sugar hog. It takes a lot of sugar to keep the lights on. If your blood sugar drops far enough, your brain can’t function right. If you get low enough, you can pass out. If you are “out” long enough you can get brain damage. It is the same as drowning.

Why does blood sugar drop? The most common cause is medication driven: if you take diabetes medications designed to lower your blood sugar, they may do too good a job now and again.

And just as the symptoms vary from person to person, so too does the blood sugar level where you’ll feel them. There is no magic number. People who tend to experience hypo unawareness a lot start feeling it at lower and lower numbers over time, until they pass out before (or at the instant) that they are aware of the low blood sugar.

The condition can sometimes be reversed by running your blood sugar high for a few months to try and re-boot the system. If that fails, the best bet for safety is to get a continuous glucose monitor that can keep tabs on your blood sugar every few minutes and give you a head’s up when trouble starts.

I suffer from hypo unawareness myself.