Diabetes & Hyperosmolar Hyperglycemic Syndrome

Diabetic ketoacidosis (DKA) usually gets top billing when it comes to the acute complications of diabetes—and rightly so, as it can cause coma or death for those with undiagnosed or diagnosed diabetes. It’s less common in those with type 2, but there’s another, similar condition that may plague those with type 2.

Hyperosmolar Hyperglycemic Nonketotic Syndrome (HHNS) results from the same underlying causes as DKA, and like DKA, it can result in death if untreated. HHS and DKA are the two most common life-threatening complications of diabetes, according to DiabetesSpectrum. DKA is much more common in those with type 1 diabetes, and HHNS is more common in those with type 2 (though both conditions are possible in either type).

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What is HHNS?

HHNS has many characteristics of DKA, but the main difference is that in HHNS, there is too little insulin present to keep blood sugar from going high, but still enough to prevent ketoacidosis. This is why HHNS is more common in those with type 2, and it often manifests in those with undiagnosed or untreated diabetes. Because there is still some circulating insulin, HHNS usually sets slowly, over days or even weeks, and it causes severe dehydration.

HHNS usually occurs after or during a sickness or an infection that contributes to hyperglycemia. These conditions may also contribute to dehydration. HHNS is more common in older adults (between 55 and 70), and it’s common for HHNS to present in a nursing home patient as they may not notice symptoms. Sometimes the condition goes unnoticed until a person displays altered senses.

As blood sugar rises, the body tries flush out excess glucose through the urine. At first someone will produce a lot of urine and then much less as dehydration sets in. Blood becomes thicker, exacerbating high blood sugar, and the kidneys are no longer able to properly flush out excess glucose. HHNS can lead to brain swelling, abnormal heart rhythms, seizures, stroke, coma, and organ failure. Untreated, HHNS can be fatal.

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Signs and Symptoms

Watch out for HHNS by knowing the warning signs:

  • Blood sugar over 600 mg/dl (contact a doctor longer before this point)
  • Extreme thirst (at least in the beginning stages)
  • Dry mouth
  • Increased urination
  • Weakness on one side of body
  • Fatigue
  • Vision loss
  • Confusion or hallucinations
  • Fever

If you are experiencing these symptoms, talk to a medical professional right away.

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Risk Factors

People with type 2 diabetes, prediabetes, or undiagnosed diabetes are most at risk for HHNS, and risk is highest after or during an infection (often a urinary tract infection or pneumonia), an illness, stress, poor diabetes compliance, or an acute condition like an accident or trauma.

Other risk factors include:

  • Advanced age
  • A chronic health condition like heart failure or kidney disease
  • Using certain medications like corticosteroids, thiazides, sympathomimetic agents, pentamidine, and water pills.
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The best ways to prevent HHNS are to stay consistent with diabetes management and to check blood sugar regularly. Being vigilant about staying hydrated when sick or fighting infection can also help. Because older adults with compromised health are at the highest risk for HHNS, it’s especially important that caregivers and loved ones know what to look for.

Treatment will depend on the underlying cause of HHNS, but will generally include monitoring and correcting both hyperglycemia and dehydration.

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