A hyperosmolar state is a life-threatening condition that develops when a person with type 2 diabetes has very high blood sugar—often over 600 millligrams per deciliter (mg/dL).

Most often, a hyperosmolar state develops when a person has an illness, such as a severe case of the flu or other infection, or has a heart attack. It can also develop if a person takes medications that remove fluids from the body (diuretics). Mental alertness can be affected, especially if the person does not drink enough liquids. Older people are at increased risk for developing a hyperosmolar state.

Symptoms of a hyperosmolar state include:

• Increased urination for several days.
• Dehydration, which develops because the person doesn't drink enough liquids.
• A change in alertness from generalized fatigue to stupor, coma, or seizures. These changes may be mistaken for a stroke or mental illness.

Hyperosmolar state is treated in a hospital with insulin to reduce the blood sugar level and extra fluids through a vein (IV) to replace the lost fluids.

The best way to prevent a hyperosmolar state is to treat high blood sugar levels early and drink sufficient liquids.