What is a diabetic coma?

Diabetic coma is a serious condition that can be life threatening, and usually occurs in patients who experience extremely high or low levels of blood sugar. This is a rare condition where a patient is alive, but unable to respond to stimulation such as sound or sight. In other words, diabetic coma happens when a diabetic patients becomes unconscious. When you have high levels of blood glucose, you can experience fatigue, stomach pain, and shortness of breath. On the other hand, low levels of blood glucose can make you feel dizzy and weak. The symptoms can worsen until you fall into a coma. If diabetic coma is not treated, it can be fatal. However, the good news is that diabetic coma is preventable. Usually, when you carefully follow your diabetes treatment plan, you can prevent low blood sugar (hypoglycemia) and high blood sugar (hyperglycemia) from advancing to a more serious condition, i.e. diabetic coma. If you lapse into a diabetic coma, you will need emergency medical care. If you start to experience signs of hypoglycemia or hyperglycemia, you should seek medical attention immediately—especially if the symptoms get worse.

Types of diabetic coma

There are 3 common types of diabetic coma:

  • Severe hypoglycemia in patients with diabetes

Hypoglycemia can be treated, but a diabetic patient may lose consciousness if it becomes severe.

  • Hyperosmolar nonketotic coma

Hyperosmolar nonketotic coma usually occurs in type 2 diabetic patients who have very high blood sugar levels.

  • Diabetic ketoacidosis

If diabetic ketoacidosis advances without proper treatment, a diabetic patient may lose consciousness as result of extremely high blood glucose, fatigue, and dehydration.

Signs and symptoms of diabetic coma

There are certain warning signs which may alert you that you are at risk of suffering from diabetic coma. Watch out for signs and symptoms of hypoglycemia or hyperglycemia that usually occur before you develop diabetic coma. In case you experience any of the following symptoms of hyperglycemia or hypoglycemia, call your doctor for medical advice. He may advise you to check your blood sugar levels and carefully follow a different treatment plan depending on the results.

Symptoms of hypoglycemia

  • Weakness
  • Hunger
  •  Confusion
  • Sweating
  • Anxiety
  • Nervousness
  • Lightheadedness

Symptoms of hyperglycemia

  • Rapid heartbeat
  • Frequent urination
  • Fatigue
  • Fruity smelling breath
  • Dry mouth
  • Vomiting and nausea
  • Increased thirst
  • Shortness of breath

A diabetic coma is a serious medical condition. If you experience the above symptoms of low blood sugar or high blood sugar and you feel that you may pass out, call immediately for emergency help.


Diabetic coma is normally caused by extremely low or high levels of blood sugar.

The following are the main causes of diabetic coma:

  • Severe hypoglycemia

For your brain to function properly, it requires glucose. In case you experience extremely low blood sugar, you may lose your consciousness. Hypoglycemia can occur when you skip meals or you engage in excessive physical exercise. Also, if you take a large dose of insulin medication, you may experience low blood sugar. If left untreated, severe hypoglycemia can lead to a diabetic coma.

  • Diabetic hyperosmolar syndrome

In case you experience extremely high blood sugar that exceeds 33.3mmol/L, then you may develop a serious condition called diabetic hyperosmolar syndrome. The excess glucose in the bloodstream is normally excreted via urine, which carries with it lots of body fluids. If diabetic hyperosmolar syndrome is left untreated, it can cause severe dehydration and diabetic coma.

  • Diabetic ketoacidosis

Diabetic ketoacidosis is a serious condition where your body produces too many ketones, which decreases your body’s ability to produce insulin. This means that glucose cannot be converted into energy. When your muscle cells lack the energy it needs to function properly, it will start to break down fat into energy. If high ketone levels are not treated, diabetic ketoacidosis may develop which may cause diabetic coma.


Before you begin treatment for diabetic coma, your doctor may need to perform different tests to check your blood glucose and ketone levels. Other tests may be done to check the amount of phosphate, sodium, and potassium in your bloodstream. The type of treatment that your doctor will use to treat diabetic coma will be based on whether you have extremely low or high blood sugar. In case you have high blood glucose, your doctor may prescribe IV fluids to help restore fluids, insulin therapy to help your tissue absorb glucose from the bloodstream, and sodium or potassium supplements that will help your body cells to function properly. If you have extremely low blood sugar, a glucagon injection may be prescribed to help increase your blood sugar levels. When your blood glucose is back to normal, you should regain conscious.

Disclaimer: Please note that the contents of this community article are strictly for informational purposes and should not be considered as medical advice. This article, and other community articles, are not written or reviewed for medical validity by Canadian Insulin or its staff. All views and opinions expressed by the contributing authors are not endorsed by Canadian Insulin. Always consult a medical professional for medical advice, diagnosis, and treatment.