What Is a Diabetic Coma?

A diabetic coma can be a life-threatening emergency that occurs when an individual who has diabetes suffers from low blood glucose (hypoglycemia) or high blood glucose (hyperglycemia). Signs of a diabetic coma include an altered mental state, inability to speak, visual problems, drowsiness, weakness, headache, and restlessness.

In general, it is important for people with diabetes to check their blood sugar regularly and take their medication as prescribed by their healthcare provider. If you are in the presence of a person with diabetes who needs attention due to a diabetic coma, you should call 911 immediately.

woman checking blood sugar

Tempura / Getty Images


A diabetic coma can be caused by either high or low blood sugar.

High Blood Sugar

High blood sugar (hyperglycemia) occurs when the body doesn’t have enough insulin and there is too much sugar in the blood.

Symptoms of hyperglycemia include:

  • Blurred vision
  • Headache
  • Fatigue
  • Frequent urination
  • Increased hunger and/or thirst

Different types of hyperglycemia include:

  • Diabetic ketoacidosis: Known as a hyperglycemic emergency, this occurs when the body breaks down fat at a rate that is too fast for the body to handle. When this happens, the liver processes the fat into ketones, causing the blood to become acidic. Diabetic ketoacidosis is more common in people with type 1 diabetes and less common in people with type 2 diabetes.
  • Diabetic hyperglycemic hyperosmolar syndrome (HHS): Known as an extremely high blood sugar level without ketones, this is also considered a complication that is more common with patients who have type 2 diabetes. HHS is a condition that involves extreme dehydration, high blood glucose, and decreased alertness.

Importance of Checking Your Blood Sugar

As a patient with diabetes, it is always important to check your blood sugar. If you have any questions or concerns, contact your healthcare professional. They can help you understand and manage your numbers and condition.

Low Blood Sugar 

Low blood sugar (hypoglycemia) happens when the body doesn’t have enough glucose. This can lead to symptoms such as:

  • Dizziness
  • Shakiness
  • Difficulty speaking
  • Fast breathing
  • Hunger
  • Nausea
  • Feeling anxious or weak

If a person has diabetes, hypoglycemia can, at times, be a side effect of diabetes medication.

Glucose is an important factor for the body. The liver releases glucose, as needed, when the blood sugar levels start to fall. It is always important to check with your healthcare professional if you have questions or concerns. 


It is helpful to know the signs and symptoms of both a hypoglycemic coma and a hyperglycemic coma, as they differ.

Hypoglycemic Coma

If a person is lapsing into a hypoglycemic coma, it feels similar to fainting, including:

  • A strong throbbing pulse felt over one of the arteries in the body
  • Sweaty skin
  • Disorientation
  • Anxiety
  • Irritability

These symptoms occur before consciousness is lost. If not treated quickly, brain damage is possible.

When a patient experiences a diabetic coma due to hypoglycemia, they will typically receive treatment including glucagon, intravenous fluids, and a 50% dextrose solution.

Hyperglycemic Coma

When a hyperglycemic coma occurs, it is known to have a slow onset with drowsiness that deepens over time. Other symptoms include:

  • Dehydration
  • A weak pulse
  • Bounding
  • Ketosis

When a hyperglycemic coma occurs, a person will typically receive treatment including insulin; supplements of phosphate, sodium, and potassium; and intravenous fluids.

When to Seek Medical Care

If a person is showing any symptoms of a diabetic coma, it is important to call 911 immediately so they can get the proper care that is needed as soon as possible.

Risk Factors

If an individual has diabetes, they are at risk for a diabetic coma. The type of diabetes is an indicator of the type of coma they may experience.

  • If a person has type 1 diabetes, they need insulin and tend to have a wider range in blood glucose levels, so if they experience a diabetic coma, it is typically due to hypoglycemia or ketoacidosis.
  • If a person has type 2 diabetes and experiences a diabetic coma, it is likely due to diabetic hyperosmolar syndrome or extremely high blood glucose levels.

Other risk factors include:

  • Surgery
  • Illness
  • Poor management of the diabetic condition
  • Skipping insulin doses
  • The use of drugs and alcohol


Blood sugar levels that occur during a diabetic coma include:

  • Blood sugar that is higher than 300 mg/dL two times in a row for no reason
  • Blood sugar that is low, less than 70 mg/dL, and the numbers don’t increase after three treatments

If an individual has symptoms of a diabetic coma, call for emergency medical attention and inform responders that the person has diabetes. It is also recommended that the individual with diabetes wear a medical identification necklace or bracelet.


Treatments for people with diabetes who have high blood sugar include supplements of:

  • Sodium
  • Potassium
  • Phosphate
  • Insulin
  • Intravenous fluids to restore water to the tissues

If there is any type of infection, treatment will be conducted for that as well.

If an individual experiences hypoglycemia, treatments include:

  • Intravenous dextrose to raises blood glucose levels
  • Glucagon injection, which causes the blood sugar level to rise quickly

If you are with a person who is going into a diabetic coma, call 911, make sure they are in a comfortable position, and check their blood sugar.


If you have diabetes, preventative measures can be taken to reduce the risk of diabetic coma, including:

  • Educate yourself so you know how to navigate your condition. There are Certified Diabetes Educators that help patients understand how to live with diabetes.
  • Educate friends and family so they know what to do in the event that a diabetic coma occurs.
  • Eat a proper diet for your condition.
  • Follow the directions of insulin doses and prescribed medication.
  • Check your blood sugar and ketone levels at the recommended times given by your healthcare provider.
  • Avoid habits and foods that will negatively affect your condition.
  • Wear a medical identification bracelet or necklace so medical professionals know that you have diabetes.


A diabetic coma can cause brain damage and/or death depending on the severity. Treatment depends on the type of diabetes as well as any other health conditions.

When to Call a Healthcare Provider

If you or someone you are with has blood sugar levels that are too high or too low and feels as if they are going faint or are extremely dizzy, it is best to call 911 and go to the hospital.

In some instances, a patient can call their healthcare professional, who can tell them the proper steps needed to help them. This is a good topic for discussion during a well visit.

A Word From Verywell

A diabetic coma can be an intense experience for all involved. If you or someone you know has diabetes, it is important to follow the recommendations of your healthcare professional.

Do your part to educate yourself the best you can so you can properly manage your condition between healthcare provider visits. There are a lot of resources that help manage diabetes. Have a discussion with your healthcare provider in regards to finding the right resources, treatments, and support groups.

6 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Cleveland Clinic. Diabetic coma.

  2. Cleveland Clinic. High blood sugar hyperglycemia (high blood sugar).

  3. MedlinePlus. Diabetic ketoacidosis.

  4. MedlinePlus. Diabetic hyperglycemic hyperosmolar syndrome.

  5. MedlinePlus. Hypoglycemia.

  6. Hillson R. Dizziness in diabetesPractical Diabetes. 2018;35(2):41-42. doi:10.1002/pdi.2158

By Yvelette Stines
Yvelette Stines, MS, MEd, is an author, writer, and communications specialist specializing in health and wellness.