A diabetic coma is a life-threatening diabetes complication that causes unconsciousness. If you have diabetes, dangerously high blood sugar (hyperglycemia) or dangerously low blood sugar (hypoglycemia) can lead to a diabetic coma.
If you lapse into a diabetic coma, you’re alive — but you can’t awaken or respond purposefully to sights, sounds or other types of stimulation. Left untreated, a diabetic coma can be fatal.
The prospect of a diabetic coma is scary, but fortunately you can take steps to help prevent it. Start by following your diabetes treatment plan.
Prolonged blood sugar extremes — blood sugar that’s either too high or too low for too long — may cause various conditions, all of which can lead to a diabetic coma.
Diabetic ketoacidosis. If your muscle cells become starved for energy, your body may respond by breaking down fat stores. This process forms toxic acids known as ketones. Left untreated, diabetic ketoacidosis can lead to a diabetic coma.
Diabetic ketoacidosis is most common in people who have type 1 diabetes, but it can also affect people who have type 2 diabetes or gestational diabetes.
Diabetic hyperosmolar syndrome. If your blood sugar level tops 600 milligrams per deciliter (mg/dL), or 33.3 millimoles per liter (mmol/L), the condition is known as diabetic hyperosmolar syndrome.
When your blood sugar gets this high, your blood becomes thick and syrupy. The excess sugar passes from your blood into your urine, which triggers a filtering process that draws tremendous amounts of fluid from your body.
Left untreated, diabetic hyperosmolar syndrome can cause life-threatening dehydration and a diabetic coma. Diabetic hyperosmolar syndrome is most common in middle-aged and older adults who have type 2 diabetes.
Hypoglycemia. Your brain needs glucose to function. In severe cases, low blood sugar may cause you to pass out. Hypoglycemia can be caused by too much insulin or not enough food. Exercising too vigorously or drinking too much alcohol can have the same effect.
Signs and symptoms are influenced by the severity of the hypoglycemia. With longstanding diabetes, however, you may lose the early warning signs — such as hunger, shakiness and perspiration — and may only develop symptoms when your blood sugar is dangerously low. This is called hypoglycemia unawareness.
Before developing a diabetic coma, you’ll usually experience signs and symptoms of high blood sugar or low blood sugar.
High blood sugar (hyperglycemia)
If your blood sugar level is too high, you may experience:
- Increased thirst
- Frequent urination
- Nausea and vomiting
- Shortness of breath
- Stomach pain
- Fruity breath odor
- A very dry mouth
- A rapid heartbeat
- Low blood sugar (hypoglycemia)
Signs and symptoms of a low blood sugar level may include:
- Shakiness or nervousness
- Dizziness or light-headedness
- Difficulty speaking
Some people, especially those who’ve had diabetes for a long time, develop a condition known as hypoglycemia unawareness and won’t have the warning signs that signal a drop in blood sugar.
If you experience any symptoms of high or low blood sugar, test your blood sugar and follow your diabetes treatment plan based on the test results. If you don’t start to feel better quickly, or you start to feel worse, call for emergency help.
A diabetic coma is a medical emergency. If you feel extreme high or low blood sugar signs or symptoms and think you might pass out, call 911 or your local emergency number. If you’re with someone with diabetes who has passed out, call for emergency help, and be sure to let the emergency personnel know that the unconscious person has diabetes.