(Low Blood Glucose; Low Blood Sugar)


Glucose is a type of sugar. It is your body's main source of energy. Hypoglycemia is a condition where the level of glucose in your blood becomes low enough to cause symptoms. When blood glucose drops too low, your body does not have enough energy to function properly.


Medications for diabetes are the most common cause, particularly when combined with the following factors:
Reactive hypoglycemia may also occur in people without diabetes. It is thought to be rare.
Other causes of hypoglycemia include:

Risk Factors

Factors that may increase your chance of hypoglycemia include:


Symptoms may come on slowly or suddenly. Hypoglycemia may cause:
As hypoglycemia worsens, it may cause:
If you have frequent hypoglycemia, you may lose many of the early symptoms and be at particular risk of sudden loss of consciousness, seizure, or bizarre behavior. This could affect your ability to operate machinery or a motor vehicle. You will need to discuss any special instructions with your doctor.


You will be asked about your symptoms and medical history. A physical exam will be done.
If hypoglycemia is suspected, your doctor will try to document your low blood sugar. Your blood glucose levels will be measured while you are having symptoms.
If you do not have diabetes, and you do not take medications that lower your blood sugar levels, other tests may be done to see if and why you are having low blood sugar levels. These tests may include checking your blood levels after periods of not eating.


Talk with your doctor about the best treatment plan for you. Options include:


Symptoms of low blood sugar can be relieved quickly by:
  • Eating sugar in a rapidly absorbable form, such as:
    • Fruit juice
    • Sugared soft drink
    • Table sugar in water
    • Honey or corn syrup
  • Taking glucose tablets
  • IV glucose (in severe cases)


Some people who have prolonged or severe hypoglycemia take glucagon. Glucagon is an injectable hormone. It raises blood sugar levels.


Some cases of hypoglycemia are caused by a tumor. In this case, the tumor may need to be removed.


To help reduce your chance of hypoglycemia:
If you are prone to severe hypoglycemia:


American Diabetes Association

Hypoglycemia Support Foundation


Canadian Diabetes Association

Health Canada


Hypoglycemia. National Diabetes Information Clearinghouse website. Available at: Updated November 6, 2012. Accessed September 30, 2014.

Hypoglycemia (low blood glucose). American Diabetes Association website. Available at: Updated September 16, 2014. Accessed September 30, 2014.

Hypoglycemia in diabetes. EBSCO DynaMed website. Available at: Updated September 29, 2014. Accessed September 30, 2014.

Hypoglycemia in persons without diabetes. EBSCO DynaMed website. Available at: Updated September 29, 2014. Accessed September 30, 2014.

Revision Information