Severely high blood sugar turns your blood thick and syrupy. The excess sugar passes from your blood into your urine, which triggers a filtering process that draws tremendous amounts of fluid from your body. Left untreated, this can lead to life-threatening dehydration and a diabetic coma.

Why does hyperglycemia cause loss of consciousness?

Causes of diabetic coma

A diabetic coma occurs when blood sugar levels become either too low or too high. The cells in your body require glucose to function. High blood sugar, or hyperglycemia, can make you dehydrated which can cause you to lose consciousness.

How does hypoglycemia lead to coma?

For people with type 2, a diabetic coma may be caused by either hypoglycemia or very high blood sugar, called diabetic hyperosmolar syndrome. That's when your body tries to get rid of extra sugar by passing it into your urine. Over days or weeks, this can cause life-threatening dehydration and, eventually, a coma.