Diabetes-Related Coma

Diabetes-related coma is a life-threatening emergency that can affect you if you have diabetes. In a diabetes-related coma, you're unconscious and unable to respond to your environment. You are either suffering from high blood glucose (hyperglycemia) or low blood glucose (hypoglycemia). You need immediate medical attention if you go into a diabetes-related coma.


What is a diabetes-related coma?

Diabetes-related coma is a life-threatening emergency that can happen to you if you have diabetes. In a diabetes-related coma, you’re unconscious and unable to respond to your environment. You’re either suffering from high blood glucose (hyperglycemia) or low blood glucose (hypoglycemia). You need immediate medical attention if you go into a diabetes-related coma.


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Symptoms and Causes

What are the causes of diabetes-related coma?

Diabetes-related coma is mainly caused by an extremely high or low blood sugar level. One of these conditions is diabetes-related hyperosmolar syndrome. It happens in people with Type 2 diabetes. If you develop this condition:

  • Your blood sugar could be as high as 600 mg/dL.
  • Your urine won’t contain ketones usually.
  • Your blood will be much thicker than normal.

Another condition is diabetes-related ketoacidosis, which is more common in people with Type 1 diabetes. Things to know about this condition include:

  • It could happen with a blood sugar as low as 250 mg/dL or even lower in some cases.
  • Your body uses fatty acids instead of glucose for fuel.
  • Ketones develop in your urine and bloodstream.

What are the symptoms of a diabetes-related coma?

The following symptoms are your body’s warning signs that your blood sugar (glucose) is too high or too low.

Whenever you have these symptoms, check your blood sugar. If it is too high or too low, treat it according to your healthcare provider’s instructions to prevent a diabetes-related coma. If you have had diabetes for a long time, you may fall into a coma without showing any of the symptoms.

Some symptoms of hyperglycemia (high blood glucose) are:

  • Tiredness.
  • Abdominal pain.
  • Shortness of breath.
  • Increased urination.
  • Weak pulse.
  • Drowsiness.

Other symptoms of high blood sugar include:

  • Walking unsteadily.
  • Increased thirst.
  • Rapid heart rate.
  • Dry mouth.
  • Fruity smell to your breath.
  • Hunger.

Low blood glucose (hypoglycemia) also has signs and symptoms. These include:

  • Weakness and tiredness.
  • Sweating.
  • Fast breathing.
  • Shakiness, nervousness and/or anxiety.
  • Nausea.
  • Confusion and problems communicating.
  • Light-headedness, dizziness.
  • Hunger.

When blood sugar is too low, the brain doesn’t receive enough fuel. This can be caused by:

  • Drinking too much alcohol.
  • Eating too little.
  • Exercising too much.
  • Taking too much insulin.

What are the risk factors for diabetes-related coma?

While anyone who has diabetes is at risk for a diabetes-related coma, the causes depend on the type of diabetes:

  • People with Type 1 diabetes have a greater chance of going into a diabetes-related coma as a result of diabetes-related ketoacidosis or hypoglycemia. This is because people with Type 1 diabetes always need insulin and have a wider range in their blood glucose levels than people with Type 2 diabetes.
  • People with Type 2 diabetes have a greater chance of going into a diabetes-related coma from diabetes-related hyperosmolar syndrome than from diabetes-related ketoacidosis or hypoglycemia.

Other risks that can lead to coma in anyone who has diabetes include:

  • Surgery.
  • Trauma.
  • Illness.
  • Insulin delivery problems.
  • Poor diabetes management.
  • Drinking alcohol.
  • Skipping doses of insulin.
  • Using illegal substances.

What are the complications of diabetes-related coma?

Complications of a diabetes-related coma include permanent brain damage and death.


Diagnosis and Tests

When is it necessary to call a doctor if you have diabetes?

Call a healthcare provider in the following situations:

  • If you have diabetes and your blood sugar is 300 mg/dL or higher two times in a row for an unknown reason.
  • If you have a low blood sugar (less than 70 mg/dL) that has not come up after three treatments, call your healthcare provider or 911.
  • If you see a person with diabetes who appears confused, they may be having a low blood sugar episode. Left untreated, the low blood sugar could lead to a diabetes-related coma. If the person is still able to follow instructions, give him or her something to drink or eat and call for an ambulance or 911.
  • If you see someone with diabetes become unresponsive, call 911.

If you do call 911, let the responders know that the person has diabetes if they’re not able to communicate. If you do have diabetes, you may want to wear a medical identification item like a bracelet or necklace.

When you are taken to a healthcare facility, providers will do a physical examination and take blood to determine levels of glucose, ketones and other substances.

Management and Treatment

How is diabetes-related coma treated?

If you go into a diabetes-related coma, you need treatment immediately. You’re at risk for brain damage or death if there is any delay in responding.

If your blood sugar is too high, you’ll receive:

  • Intravenous fluids.
  • Supplements of phosphate, sodium, and potassium.
  • Insulin.

If your blood sugar is too low, you will receive:

  • Glucagon (a hormone to increase blood sugar).
  • Intravenous fluids.
  • 50% dextrose solution.


Can a diabetes-related coma be prevented?

You can help yourself prevent a diabetes-related coma by taking steps to keep your blood sugar in the target ranges. Meeting with a Certified Diabetes Educator (CDE) is an important part of understanding how to care for your diabetes. The CDE will help you be aware of symptoms for high and low blood sugar levels and how best to manage your condition.

It's also important for your family, friends and coworkers to understand how to help you if you need help. Let them know about the symptoms of high and low blood sugar.

In terms of food and drink, here are some tips for preventing diabetes-related coma:

  • Learn about foods that affect your blood sugar and the best meal plan for you.
  • Don’t skip meals.
  • Keep treatment for a low blood sugar with you at all times (example: four glucose tabs, a small juice box, or five Life Savers®).
  • Avoid drinking too much alcohol.
  • Ask your healthcare provider to prescribe a glucagon kit and teach a support person how to use it in case you ever have severe low blood sugar.

These are other recommendations to help you manage your blood glucose levels:

  • Check and record blood sugar levels at the times recommended by your healthcare provider.
  • Follow instructions for proper dosage and timing of medications and insulin.
  • Learn how different types of exercise affect your blood sugar.
  • Check your urine for ketones when blood sugar levels are high.
  • Ask your healthcare provider when and how you should test for ketones.
  • Check urine ketones when you have symptoms of diabetes-related ketoacidosis (DKA).
  • Consider using a continuous glucose monitor that sends an alert if sugar levels are too low or too high.
  • Learn how to manage stress.
  • Wear a medical identification necklace or bracelet to alert first responders that you have diabetes.
Medically Reviewed

Last reviewed by a Cleveland Clinic medical professional on 12/02/2020.

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