Diabetic Hyperglycemic Hyperosmolar Syndrome

Written by Ann Pietrangelo | Published on September 16, 2012
Medically Reviewed by George Krucik, MD

What is Diabetic Hyperglycemic Hyperosmolar Syndrome?

Hyperglycemic hyperosmolar syndrome (HHS) is a potentially life-threatening condition involving extremely high blood sugar (glucose) levels. According to Medscape, any illness that causes dehydration or reduced insulin activity can lead to HHS; however, it is most commonly a result of uncontrolled or undiagnosed diabetes (Medscape, 2012). Diabetic HHS is usually triggered by infection or illness, or by failure to monitor and control blood glucose.

When blood sugar gets too high, the kidneys try to compensate by removing some of the excess glucose through urination. If you do not drink enough fluids to replace the fluid you are losing, or if you drink sugary beverages, blood sugar levels spike and blood becomes more concentrated. This condition is called hyperosmolarity. Once blood becomes concentrated, it begins to draw water out of other organs, including the brain.

Among possible symptoms are excessive thirst, increased urination, and fever. Symptoms may develop slowly and increase over a period of days or weeks.

Treatment involves reversing or preventing dehydration and getting blood glucose levels under control. Prompt treatment can relieve symptoms within a few hours. Untreated, diabetic HHS can lead to serious life-threatening complications, including dehydration, shock, or coma.

If you have symptoms of HHS, go to an emergency room or call 911 for help. This is a medical emergency.

What Causes HHS?

Older people with type 2 diabetes are more likely to develop HHS. A number of factors can contribute to HHS, including:

  • extremely high blood sugar levels due to uncontrolled or undiagnosed diabetes
  • infection
  • medications that lower glucose tolerance or contribute to fluid loss
  • a recent surgery
  • coexisting conditions like stroke or heart attack
  • impaired kidney function

Warning Signs and Symptoms of HHS

HHS can happen to anyone, but is more common in older people who have type 2 diabetes.

Symptoms may begin gradually and worsen over a few days or weeks. A high blood sugar level is a warning sign of HHS. Symptoms include:

  • excessive thirst
  • high urine output
  • dry mouth
  • weakness
  • sleepiness
  • fever
  • warm skin that doesn’t perspire
  • nausea, vomiting
  • weight loss
  • leg cramps
  • vision loss
  • speech impairment
  • loss of muscle function
  • confusion
  • hallucinations

If you have symptoms of HHS, go to the emergency room or call 911 immediately.

Untreated, HHS can lead to life-threatening complications such as:

  • dehydration
  • blood clots
  • seizures
  • shock
  • heart attack
  • stroke
  • swelling of the brain (cerebral edema)
  • high blood acid levels (lactic acidosis)
  • coma

How HHS is Diagnosed

A physical exam will reveal if you are suffering from dehydration, fever, low blood pressure, or rapid heart rate. This condition is most often diagnosed with a blood test to determine your current blood sugar level–your doctor will diagnose HHS if your blood sugar is 600 mg/dL or higher.

Your doctor may perform other tests to confirm diagnosis or to gauge potential complications as a result of HHS. This testing may include:

  • blood tests to check for levels of blood sugar, ketone, creatinine, potassium, and phosphate
  • sodium glycated hemoglobin test (average blood sugar level for previous two to three months)

If the cause of HHS is not associated with diabetes, a urinalysis may be performed to diagnose diabetes. According to the Mayo Clinic, HHS may occur in people who have not yet been formally diagnosed with diabetes (Mayo Clinic, 2012).

How HHS is Treated

Due to the risk for serious complications, HHS is treated as a medical emergency. Emergency treatment will include:

  • intravenous fluids to prevent or reverse dehydration
  • insulin to lower and stabilize blood sugar levels
  • if necessary, potassium, phosphate, or sodium replacement can help return your cells to normal function

Any complications from HHS must also be addressed.

Long-Term Outlook for HHS Patients

When given promptly, treatment can improve symptoms within a few hours.

Approximately 10 to 20 percent of HHS cases end in death. Old age, severity of dehydration at time of treatment, and the presence of other illnesses all increase the risk for serious complications and death. Delayed treatment also greatly increases risk (Medscape, 2012).

Tips to Prevent HHS

The most important thing you can do to prevent HHS is to carefully monitor and control diabetes. Preventative measures include:

  • familiarize yourself with the early warning signs of HHS—and do not ignore them
  • check your blood sugar levels regularly, especially when you feel ill
  • take medications as prescribed
  • maintain a healthy diet as advised by your physician
  • exercise regularly
  • if you live alone, have a relative or neighbor on alert for emergency situations
  • teach family, friends, and coworkers the early warning signs of HHS and instruct them to seek medical care for you if you cannot do it yourself
  • purchase a medical ID bracelet or card for diabetes and always keep it with you
  • get regular medical checkups and stay current with vaccinations
  • seek medical attention promptly when symptoms appear—

failure to do so will put your life at risk

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