Hypoglycemia Unawareness

If you have diabetes, you likely know the warning signs of low blood sugar forward and backward. Your friends and family may know the signs, and your neighbors, and your dog, and your cat. Hey—the more the merrier when it comes to helping you stay safe.

The symptoms of low blood sugar can be frightening, but they also serve to let you know when you need to take immediate action. If your body becomes hypoglycemia unaware, then you may not experience the sweating, dizziness, headaches, and other distressing symptoms that coincide with a low. But then again, without those signs you could slip into severe hypoglycemia or a coma without warning.

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What is hypoglycemia unawareness?

The term is pretty self-explanatory: hypoglycemia unawareness is when the signs of hypoglycemia don’t show up and a person remains, as the name suggests, completely unaware of their low blood sugar. They will likely feel completely normal until severe hypoglycemia sets in. In rare cases, someone may also be hyperglycemia unaware.

When someone’s blood sugar drops, the body releases the hormones glucagon and epinephrine. Glucagon tells the liver to release stored glucose while epinephrine (commonly known as adrenaline) tells the liver to produce more glucose and revs up the body’s “flight or flight” response, often causing sweating, shaking, rapid heart rate, and other classic signs of hypoglycemia.

But someone with hypoglycemia will have an impaired epinephrine response and won’t exhibit the warning signs of low blood sugar. Without a reliable warning system, they could go straight into severe hypoglycemia, putting themselves at risk of becoming dangerously disoriented or passing out.

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Causes of hypoglycemia unawareness

In those with type 1 diabetes, hypoglycemia unawareness may be caused by nerve damage compromising the body’s ability to signal for epinephrine. Hypoglycemia unawareness is more common in those with type 1 because of their (generally) longer history with the disease.

Tight blood sugar control—exactly the thing we’ve been told to strive for—can also contribute to unawareness. Tight blood sugar control can actually reduce the body’s ability to tell when blood sugar is dropping. Keeping levels slightly higher for a period of time may help reset the body, but this should be done with the guidance of a doctor.

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Those who experience hypoglycemia unawareness may be less likely to wake up at night when they’re having a low and should take extra precautions such as checking levels more frequently, wearing a medical alert bracelet, using a continuous glucose monitor, or having a diabetic alert dog. Those who experience unawareness overnight may wake with abnormally high blood sugar levels as the body compensates for the low.

Hypoglycemia unawareness is more common in those who have frequent lows, have had diabetes for a long time, and who tightly control their blood sugar.

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Hypoglycemia unawareness can be treated in some cases. Speak to your doctor if your body is not warning you when you experience a low. The epinephrine response may be restored by avoiding even slight lows for several weeks under the guidance of a diabetes care team. Unawareness due to nerve damage may be harder to correct.

People with diabetes who suspect hypoglycemia unawareness should check their blood sugar extra frequently and talk to their doctor as soon as possible.

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