A person taking a sample of their blood

Hypoglycemia

Also known as low blood sugar or low blood glucose

Hypoglycemia (low blood sugar) is a condition that occurs when the glucose level in your blood drops too low. It is usually related to having diabetes, but it can be caused by other factors and conditions, such as medications, drinking too much alcohol, critical illnesses, or hormone deficiencies. Although rare, certain tumors can cause hypoglycemia.

Blood glucose below 70 milligrams per deciliter (mg/dL) is considered hypoglycemia for those with diabetes, according to the American Diabetes Association.1 Blood glucose of 70 mg/DL is considered falling glucose for those without diabetes, and the tipping point for hypoglycemia can also vary from person to person. 

For people without diabetes, hypoglycemia can not be diagnosed solely based on blood sugar level, and not by a home test. These individuals should undergo a lab test to determine their blood glucose level. A hypoglycemia diagnosis can be made if their blood glucose level is less than 55 mg/DL and they have symptoms of hypoglycemia.

Common symptoms of hypoglycemia include shakiness, fast heartbeat, sweating, headache, and fatigue

Frequently Asked Questions

  • What causes hypoglycemia?

    There can be a variety of causes. In people with diabetes, it can happen from not eating enough or frequently enough, during or after exercise, or by taking too much insulin or medication. In those without diabetes, it can be caused by drinking too much alcohol, taking certain medications that lower blood sugar, critical illnesses, hormone deficiencies, or an overproduction of insulin.

  • How do you treat hypoglycemia?

    In mild cases, it can be treated with glucose tablets or high-sugar foods or drinks every 15 minutes as needed to stabilize blood sugar. In severe cases (including loss of consciousness) in those with diabetes, prescription drugs that contain the hormone glucagon, which triggers a release of stored glucose, can be used. If blood sugar levels do not go up, urgent medical attention is needed.

  • What are the symptoms of hypoglycemia?

    Common symptoms include shakiness, a fast heartbeat, sweating, fatigue, anxiety, and hunger. If blood glucose drops dangerously low, symptoms such as confusion, vision problems, behavioral changes, slurred speech, seizures, or loss of consciousness can occur.

  • How do you test for hypoglycemia?

    Those with diabetes can use their blood glucose meter to check if their blood sugar has dropped below 70 mg/dL. Those without diabetes who have symptoms of hypoglycemia, especially recurring symptoms, should see a physician who can run blood tests, ask about your medical history, and do a physical exam to try to determine the underlying cause of the hypoglycemia.

Key Terms
tired exhausted fatigued thyroid
Causes and Risk Factors of Hypoglycemia
Man Checking Glucose
How Hypoglycemia Is Diagnosed
Page Sources
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  1. American Diabetes Association. Hypoglycemia (Low Blood sugar).

  2. American Heart Association. Carbohydrates. Updated April 16, 2018.

  3. U.S. Centers for Disease Control and Prevention. Insulin resistance and diabetes. Updated August 12, 2019.

Additional Reading