Diabetic Hyperglycemic Hyperosmolar Syndrome

Symptoms, Doctors, Treatments, Advances & More

Condition 101 About Diabetic Hyperglycemic Hyperosmolar Syndrome

What is the definition of Diabetic Hyperglycemic Hyperosmolar Syndrome?

Diabetic hyperglycemic hyperosmolar syndrome (HHS) is a complication of type 2 diabetes. It involves extremely high blood sugar (glucose) level without the presence of ketones.

What are the alternative names for Diabetic Hyperglycemic Hyperosmolar Syndrome?

HHS; Hyperglycemic hyperosmolar coma; Nonketotic hyperglycemic hyperosmolar coma (NKHHC); Hyperosmolar nonketotic coma (HONK); Hyperglycemic hyperosmolar non-ketotic state; Diabetes - hyperosmolar

What are the causes for Diabetic Hyperglycemic Hyperosmolar Syndrome?

HHS is a condition of:

  • Extremely high blood sugar (glucose) level
  • Extreme lack of water (dehydration)
  • Decreased alertness or 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.

HHS is more often 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:

  • Infection
  • 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
  • Running out of, or not taking prescribed diabetes medicines

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, you become very dehydrated. When this occurs, the kidneys are no longer able to get rid of the extra glucose. As a result, the glucose level in your blood can become very high, sometimes more than 10 times the normal amount.

The loss of water 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. This draws the water out of the body's other organs, including the brain.

Risk factors include:

  • A stressful event such as infection, heart attack, stroke, or recent surgery
  • Heart failure
  • Impaired thirst
  • Limited access to water (especially in people with dementia or who are bedbound)
  • Older age
  • Poor kidney function
  • Poor management of diabetes, not following the treatment plan as directed
  • Stopping or running out of insulin or other medicines that lower glucose level

What are the symptoms for Diabetic Hyperglycemic Hyperosmolar Syndrome?

Symptoms may include any of the following:

  • Increased thirst and urination (at the beginning of the syndrome)
  • Feeling weak
  • Nausea
  • Weight loss
  • Dry mouth, dry tongue
  • Fever
  • Seizures
  • Confusion
  • Coma

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

What are the current treatments for Diabetic Hyperglycemic Hyperosmolar Syndrome?

At the start of treatment, the goal is to correct the water loss. This will improve the blood pressure, urine output, and circulation. Blood sugar will also decrease.

Fluids and potassium will be given through a vein (intravenously). This must be done carefully. High glucose level is treated with insulin given through a vein.

What is the outlook (prognosis) for Diabetic Hyperglycemic Hyperosmolar Syndrome?

People who develop HHS are often already ill. If not treated right away, seizures, coma, or death may result.

What are the possible complications for Diabetic Hyperglycemic Hyperosmolar Syndrome?

Untreated, HHS may lead to any of the following:

  • Shock
  • Blood clot formation
  • Brain swelling (cerebral edema)
  • Increased blood acid level (lactic acidosis)

When should I contact a medical professional for Diabetic Hyperglycemic Hyperosmolar Syndrome?

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 HHS.

How do I prevent Diabetic Hyperglycemic Hyperosmolar Syndrome?

Controlling type 2 diabetes and recognizing the early signs of dehydration and infection can help prevent HHS.



Crandall JP, Shamoon H. Diabetes mellitus. In: Goldman L, Schafer AI, eds. Goldman-Cecil Medicine. 26th ed. Philadelphia, PA: Elsevier; 2020:chap 216.

Lebovitz HE. Hyperglycemia secondary to nondiabetic conditions and therapies. In: Jameson JL, De Groot LJ, de Kretser DM, et al, eds. Endocrinology: Adult and Pediatric. 7th ed. Philadelphia, PA: Elsevier Saunders; 2016:chap 42.

Sinha A. Diabetic emergencies. In: Bersten AD, Handy JM, eds. Oh's Intensive Care Manual. 8th ed. Philadelphia, PA: Elsevier; 2019:chap 59.

Latest Advances On Diabetic Hyperglycemic Hyperosmolar Syndrome

Latest Advance
  • Condition: Acute Hyperglycemic Crises with Coronavirus Disease-19 in Patients with Diabetes in Korea
  • Journal: Diabetes & metabolism journal
  • Treatment Used: Intensive Monitoring and Aggressive Supportive Care
  • Number of Patients: 2
  • Published —
This case report present patients with diabetes and severe COVID-19 infection who developed acute hyperglycemic (high blood sugar) crises in Korea.
Latest Advance
  • Condition: Type 2 Diabetes
  • Journal: Journal of the Formosan Medical Association = Taiwan yi zhi
  • Treatment Used: Glucose Cotransporter-2 Inhibitors
  • Number of Patients: 1
  • Published —
This case report describes an elderly patient with type 2 diabetes mellitus switched to sodium-glucose cotransporter-2 (SGLT-2) inhibitor who developed atypical hyperosmolar hyperglycemic (high blood sugar) state and diabetic ketoacidosis treated with insulin pump treatment and fluid supplementation.

Clinical Trials For Diabetic Hyperglycemic Hyperosmolar Syndrome

There are no recent clinical trials available for this condition. Please check back because new trials are being conducted frequently.