Hyperosmolar Hyperglycemic Nonketotic Syndrome

Hyperosmolar Hyperglycemic Nonketotic Syndrome, or HHNS, is a serious condition most frequently seen in older people. HHNS can happen to people occurring more often in people with type 2, non-insulin dependent diabetes. HHNS is usually brought on by something such as an illness or infection.


In HHNS, blood sugar levels rise, and your body tries to get rid of the excess sugar by passing it into your urine. You pass lots of urine at first. Later, as you become dehydrated (not enough water in your body), you may go to the bathroom less and your urine becomes darker. You may be very thirsty. Even if you are not thirsty, you need to drink liquids. If you do not drink enough liquids at this point, you can get dehydrated.

If HHNS continues, the severe dehydration will lead to seizures, coma and eventually death. HHNS may take days or even weeks to develop.


  • Blood sugar level over 600 mg/dl.

  • Dry, parched mouth

  • Extreme thirst (although this may gradually disappear).

  • Warm, dry skin that does not sweat

  • High fever over 101° F (38.3° C), for example.

  • Sleepiness or confusion

  • Loss of vision

  • Hallucinations (seeing or hearing things that are not there).

  • Weakness on one side of the body.

  • If you have any of these symptoms, call one of your caregivers.


The best way to avoid HHNS is to check your blood sugar regularly. Many people check their blood sugar several times a day, usually before or after meals. Talk with your caregivers about when to check and what the numbers mean. You should also talk with your caregivers about your target blood sugar range and when to call if your blood sugars are too high, too low or not in your target range. When you are sick, you will check your blood sugar more often, and drink a glass of liquid (alcohol-free and caffeine-free) every hour. Work with your team to develop your own sick day plan.


Another condition to watch signs for is ketoacidosis, which means dangerously high levels of ketones, or acids, that build up in the blood. Ketones appear in the urine when your body does not have enough insulin, and can poison the body. If not treated, you may become very sick or even comatose. This can lead to death.