Hyperglycemic hyperosmolar syndrome (HHS) is a potentially life threatening condition involving extremely high blood sugar (glucose) levels.

When your blood sugar gets too high, the kidneys try to compensate by removing some of the excess glucose through urination.

If you don’t drink enough fluids to replace the fluid you’re losing, your blood sugar levels spike. Your blood also becomes more concentrated. This can also occur if you drink too many sugary beverages.

This condition is called hyperosmolarity. Blood that’s too concentrated begins to draw water out of other organs, including the brain.

Any illness that makes you dehydrated or reduces your insulin activity can lead to HHS. It’s commonly a result of unmanaged or undiagnosed diabetes. An illness or infection can trigger HHS.

Failure to monitor and manage blood glucose levels can also lead to HHS.

Symptoms may develop slowly and increase over a period of days or weeks. Possible symptoms include:

Treatment involves reversing or preventing dehydration and managing blood glucose levels. Getting treatment right away can help relieve symptoms in a few hours.

Untreated HHS can lead to life threatening complications, including:

HHS is a medical emergency. Call 911 or get immediate medical help if you have HHS symptoms.

HHS can happen to anyone. It’s 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. The symptoms include:

Go to the emergency room or call 911 right away if you have symptoms of HHS.

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

Older people with type 2 diabetes are more likely to develop HHS.

Some factors that can contribute to HHS are:

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

A physical exam will show if you have:

Your doctor will likely use a blood test to diagnose this condition. The blood test checks your current blood sugar level. Your doctor will diagnose HHS if your blood sugar is 600 milligrams per deciliter (mg/dL) or higher.

Your doctor may perform other tests to confirm a diagnosis or see if there are any other potential complications. Tests may include blood tests to check for levels of:

Your doctor can also order a glycated hemoglobin test. This test shows your average blood sugar level for the previous 2 to 3 months.

If you have HHS but haven’t already received a diabetes diagnosis, your doctor may perform a urinalysis to see if you have diabetes.

According to the Mayo Clinic, HHS can occur in people who haven’t already received a diabetes diagnosis.

HHS is as a medical emergency due to the risk of complications. Emergency treatment will include:

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

Treatment will also address any complications from HHS, such as shock or coma.

Factors that can increase your risk of complications with HHS include:

  • advanced age
  • severity of dehydration when you’re treated
  • the presence of other illnesses when you’re diagnosed

Waiting too long to get treatment can also increase your risk of complications. Quick treatment can improve symptoms within a few hours.

The best way to prevent HHS is to monitor your diabetes carefully and manage it.

Take the following steps to help prevent HHS:

  • Know the early warning signs of HHS, and don’t ignore them.
  • Check your blood sugar levels regularly, especially when you feel sick.
  • Take your prescribed medications regularly and consistently.
  • Maintain a healthy diet as recommended by your doctor.
  • Exercise regularly.
  • If you live alone, have a relative or neighbor on alert for emergency situations.
  • Share early HHS warning signs with family, friends, and co-workers. Instruct them to seek medical care for you if you can’t do it yourself.
  • Get a medical ID bracelet or card for diabetes and always keep it with you.
  • Get regular medical checkups and stay current with vaccinations.
  • Notice HHS symptoms? Go to your doctor immediately.