Hyperosmolar Hyperglycemic Syndrome in the Elderly Diabetic

If you have diabetes, there is always the potential for developing many different types of complications that vary in duration and severity. One of the more serious conditions associated with diabetes is Hyperosmolar Hyperglycemic Syndrome or HHS. It is characterized by high blood glucose levels but without ketosis like that found in Diabetic Ketoacidosis (DKA).

What is Hyperosmolar Hyperglycemic Syndrome?

Hyperosmolar Hyperglycemic Syndrome (HHS) is referred to by a variety of names. These include:

  • Diabetic Hyperglycemic Hyperosmolar State (DHHS)
  • Hyperosmolar Nonketotic Coma (HONK)
  • Hyperosmolar Hyperglycemic State (HHS)
  • Hyperosmolar Hyperglycemic State (HGS)
  • Nonketotic  Hypertonicity (NH)
  • Hyperosmolar Nonketosis (HN)
  • Hyperosmolar Hyperglycemic Nonketotic Coma (HHNC)

With HHS, an individual is hyperosmolar which means the chemical content of the blood is now dissolved in less than the normal amount of water due to reduced fluid intake.  When you have HHS, you are also hyperglycemic meaning the levels of glucose in the blood are too high.[1] HHS is a very serious condition experienced most often by people with type 2 diabetes (T2D).

The real danger of developing HHS lies in the fact that extreme dehydration can cause blood pressure to drop. It if drops low enough, there is a risk of cardiovascular collapse.  HHS has a high mortality rate.

What causes HHS?

The root cause of HHS is extremely elevated blood glucose levels. HHS is often seen when blood glucose levels reach 600 mg/dl. The cause of the rising blood glucose may be one of several situations. The most common ones are noted as follows:[2]

Coexisting illnesses and diseases

  • Acute myocardial infarction
  • Pancreatitis
  • Cerebrovascular accident
  • Hyperthermia
  • Mesenteric thrombosis
  • Cushing’s syndrome
  • Hypothermia
  • Adrenocorticotropic hormone-producing tumors
    • Renal failure
    • Pulmonary embolus
    • Severe burns
    • Thyrotoxicosis


  • Cellulitis
  • Dental infections
  • Urinary tract infection
  • Pneumonia
  • Sepsis


  • Certain medications (calcium channel blockers, chlorpromazine (Thorazine), prednisone, diuretics, anticonvulsant medications)
  • Noncompliance to a treatment regimen
  • Substance abuse
  • Alcohol abuse
  • Undiagnosed diabetes
  • Severe dehydration
  • Vomiting
  • Diarrhea

The list of triggers for high blood glucose levels and HHS in diabetics is long. HHS is a condition that demands immediate action in the way of emergency medical care.

Who is at Risk for HHS?

Those who are at risk for HHS include those with type 2 diabetes and especially the elderly who have not been diagnosed with diabetes yet.

In fact, the elderly are among the most susceptible to developing HHS compared to other age groups. The senior may first get an infection or other illness or may become dehydrated due to lack of care or mental confusion about personal care. For this reason, the elderly living alone or in assisted living or nursing homes are more likely to experience HHS. Complicating the issue is the fact that many elderly persons are totally unaware they are diabetic and don’t discover the disease until a complication like HHS develops.

Symptoms of HHS

The symptoms of Hyperosmolar Hyperglycemic Syndrome vary according to its stage of progress. HHS can develop slowly over a period of weeks. Symptoms may range from mild thirst to unconsciousness or coma. The glucose level is usually at 600 mg/dl, or even higher if a coma occurs.

Symptoms indicating the onset of HHS include the following:[3]

  • Weakness
  • Increased thirst
  • A fever of more than 101 degrees Fahrenheit
  • Nausea
  • Lethargy
  • Confusion or decreased mental awareness
  • Convulsions or seizures
  • Prune-wrinkled skin
  • Sunken eyeballs
  • Leg cramps
  • Rapid pulse
  • Coma

Many of the symptoms are not immediately felt or noticed, or are written off as belong to some other illness. The final stages are indicated by seizures and the onset of a coma.

Treatment of HHC

HHC represents an emergency situation. The individual requires rapid medical treatment including hospitalization. Treatment usually includes the following:

  • Rehydration through intravenous fluids to restore the depleted fluids
  • Electrolyte replacement to replace minerals like potassium
  • Insulin given intravenously given

Diabetics should be aware of the conditions that can precipitate HHS and be alert to symptoms. Understanding the root cause of any specific HHS episode is important too so that a recurrence is prevented.

Prevention of HHS

In order to prevent HHS, you have to be able to recognize the symptoms. Limiting episodes of hyperglycemia is a good prevention strategy. For the elderly, it is imperative that those who care for them recognize the symptoms of diabetes and HHS, whether it’s the spouse, siblings, children, retirement home staff, visiting personal support workers (PSW) or medical professionals. Patients in an assisted living facility require monitoring during their stay for such things as excessive thirst and obvious declines in mental status. Staff and relatives should have appropriate systems in place to be able to keep track of what an individual’s normal health patterns and biological processes involve – including how much they drink and urinate. The elderly should be tested annually for diabetes to help reduce the chances of HHS appearing without prior warning. If a patient is diabetic, testing blood glucose levels should be done frequently, and the regiment of care prescribed for the diabetic patient must be closely followed.


HHS should always be taken seriously. It is a serious complication of diabetes that mainly afflicts the elderly due to lack of care. Since its main target is the elderly, many of whom already face various other medical and emotional problems, it is essential that care givers and family recognize the symptoms of HHS and ensure elderly family members or patients are regularly tested for diabetes.


[1] Levin, ME; and Pfeiffer, MA (editors) (2009). The Uncomplicated Guide to Diabetes Complications, 3rd ed. Alexandria, VA: ADA.

[2] Stoner, GD (2005). “Hyperosmolar hyperglycemic state”. American Family Physician, 71(9): 1723–1730.

[3] Fowler, M (2009). “Hyperglycemic Crisis in Adults: Pathophysiology, Presentation, Pitfalls, and Prevention.” Clinical Diabetes, 27 (1): 19-23.

This article was originally published July 12, 2012 and last revision and update of it was 9/10/2015.