Clinical Overview
Reviewed by Michael Fuller, MD

For those with diabetes, prolonged high (hyperglycemia) or low blood sugar (hypoglycemia) can cause the loss of consciousness, also known as diabetic coma. Any diabetic coma is a serious emergency and if left untreated, may result in death.

Diabetic coma results when blood sugar becomes either drastically elevated or extremely low, resulting in unconsciousness. Typically there are warning signs that a diabetic coma may occur; these are different depending on the cause of the coma (high or low blood sugar).

If blood sugar is too high, warning signs of diabetic coma may include:

• Increased thirst
• Frequent urination
• Dry mouth
• Nausea
• Vomiting
• Shortness of breath

If blood sugar is too low, warning signs may include:

• Shakiness or nervousness
• Fatigue
• Sweatiness
• Hunger
• Irritability
• Confusion

Prolonged highs or lows in blood sugar can lead to various complications, all of which can culminate in diabetic coma. For example:

• When muscle cells are starved for energy because there is not enough glucose reaching cells, ketoacidocis develops and can progress to coma.
• Diabetic hyperosmolar syndrome develops when blood sugar is very high, and the body begins filtering massive quantities of fluid out of the body. Diabetic hyperosmolar syndrome can cause severe dehydration, loss of consciousness, and brain damage or death.
• Hypoglycemia develops when the brain does not get enough glucose to function properly.

Last updated: Dec-17-07