Diabetic hyperglycemic hyperosmolar syndrome
Diabetic hyperglycemic hyperosmolar syndrome (HHS) is a complication of type 2 diabetes. It involves extremely high blood sugar (glucose) levels without the presence of ketones. Ketones are waste products of fat breakdown.
Hyperglycemic hyperosmolar coma; Nonketotic hyperglycemic hyperosmolar coma (NKHHC); Hyperosmolar nonketotic coma (HONK); Hyperglycemic hyperosmolar non-ketotic state
Diabetic hyperglycemic hyperosmolar syndrome is a condition of:
- Extremely high blood sugar (glucose) level
- Extreme lack of water (dehydration)
- Decreased consciousness (in many cases)
Buildup of ketones in the body (ketoacidosis) may also occur. But it is unusual and is often mild compared with diabetic ketoacidosis.
This condition is usually seen in people with type 2 diabetes who don't have their diabetes under control. It may also occur in those who have not been diagnosed with diabetes. The condition may be brought on by:
- Other illness, such as heart attack or stroke
- Medicines that decrease the effect of insulin in the body
- Medicines or conditions that increase fluid loss
Normally, the kidneys try to make up for a high glucose level in the blood by allowing the extra glucose to leave the body in the urine. But this also causes the body to lose water. If you do not drink enough water, or you drink fluids that contain sugar and keep eating foods with carbohydrates, the kidneys can no longer get rid of the extra glucose. As a result, the glucose level in your blood can become very high.
The loss of water (dehydration) also makes the blood more concentrated than normal. This is called hyperosmolarity. It is a condition in which the blood has a high concentration of salt (sodium), glucose, and other substances that normally cause water to move into the bloodstream. This draws the water out of the body's other organs, including the brain. Hyperosmolarity creates a cycle of increasing blood glucose levels and dehydration.
Risk factors include:
- A stressful event such as infection, heart attack, stroke, or recent surgery
- Congestive heart failure
- Impaired thirst
- Limited access to water (especially in patients with dementia or who are bedbound)
- Older age
- Poor kidney function
- Poor management of diabetes -- not following the treatment plan as directed
- Stopping insulin or other medications that lower glucose levels
Symptoms may include any of the following:
- Dry mouth, dry tongue
- Increased thirst
- Increased urination (at the beginning of the syndrome)
- Weight loss
Symptoms may get worse over days or weeks.
Other symptoms that may occur with this disease:
- Loss of feeling or function of muscles
- Problems with movement
- Speech impairment
Exams and Tests
The doctor or nurse will examine you and ask about your symptoms and medical history. The exam may show that you have:
- Extreme dehydration
- Fever higher than 100.4° Fahrenheit
- Increased heart rate
- Low systolic blood pressure
Test that may be done include:
- Blood osmolarity (concentration)
- BUN and creatinine levels
- Blood sodium level
- Ketone test
- Blood glucose
Evaluation for possible causes may include:
The goal of treatment is to correct the dehydration. This will improve the blood pressure, urine output, and circulation.
Fluids and potassium will be given through a vein (intravenously). High glucose level is treated with insulin given through a vein.
Patients who develop this syndrome are often already ill. The death rate with this condition is as high as 40%.
When to Contact a Medical Professional
This condition is a medical emergency. Go to the emergency room or call the local emergency number (such as 911) if you develop symptoms of diabetic hyperglycemic hyperosmolar syndrome.
Controlling type 2 diabetes and recognizing the early signs of dehydration and infection can help prevent this condition.
Buse JB, Polonsky KS, Burant CF. Type 2 diabetes mellitus. In: Melmed S, Polonsky KS, Larsen PR, Kronenberg HM, Larsen PR, eds. Williams Textbook of Endocrinology. 12th ed. Philadelphia, PA: Elsevier Saunders; 2011:chap 31.
Inzucchi SE, Sherwin RS. Type 2 diabetes. In: Goldman L, Schafer AI, eds. Goldman's Cecil Medicine. 24th ed. Philadelphia, PA: Elsevier Saunders; 2011:chap 237.
Reviewed By: Brent Wisse, MD, Associate Professor of Medicine, Division of Metabolism, Endocrinology & Nutrition, University of Washington School of Medicine, Seattle, WA. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.