Exploring the Causes of Blood Sugar Drop and How to Manage It Effectively

Blood sugar drops from skipping meals, too much insulin or diabetes medicine, intense exercise, or alcohol.

Causes

• Skipping meals or fasting.
• Too much insulin or diabetes medicine.
• Strenuous exercise.
• Alcohol on an empty stomach.
• Rarely, insulinoma or liver disease.

Definition

Low blood sugar is below 70 mg/dL.

Symptoms

Shaking, sweating, hunger, dizziness, confusion.

Fix

Take 15 grams of fast carbs (juice or glucose tablets), recheck in 15 minutes.

Emergency

If someone is unconscious, call 911.

Hypoglycemia definition

Low blood sugar, or hypoglycemia, is usually defined as a glucose level below 70 mg/dL (3.9 mmol/L). Level 2 is under 54 mg/dL, and level 3 is a severe event with altered mental status that needs help from another person.

In people with diabetes

• Too much insulin or sulfonylurea medication.
• Skipped or delayed meals.
• Eating fewer carbohydrates than planned.
• More exercise than usual.
• Drinking alcohol, especially on an empty stomach.

In people without diabetes

• Reactive hypoglycemia, 2 to 4 hours after meals.
• Fasting for long periods.
• Heavy alcohol use.
• Liver, kidney or heart disease.
• Hormone deficiencies such as cortisol deficiency.
• Insulinoma, a rare tumor of the pancreas.
• Certain medicines.
• Gastric bypass surgery.

Symptoms

Shakiness, sweating, hunger, fast heartbeat, anxiety, headache, blurred vision, irritability, confusion. In severe cases: seizures and unconsciousness.

Rule of 15

Eat or drink 15 grams of fast acting carbohydrate, such as 4 ounces of juice, regular soda, or glucose tablets. Recheck after 15 minutes, and repeat if still below 70. Then eat a snack or meal.

Emergency

If the person is unconscious or cannot swallow, do not give food or drink. Give glucagon if available and call 911.

Prevention

Monitor glucose, eat regular meals, balance medication and exercise, and talk to your care team.

See a doctor

If you have repeated low blood sugar without diabetes, a clinician can check with fasting tests and review.

Definitions and the rule of 15

Hypoglycemia is generally defined as blood glucose below 70 mg/dL, and level 2 hypoglycemia is below 54 mg/dL, according to the American Diabetes Association. Symptoms include shakiness, sweating, hunger, headache, fast heartbeat, confusion and irritability. For a mild episode in a person who is awake, follow the rule of 15: eat or drink 15 grams of fast carbohydrate, such as 4 ounces of juice or 3 to 4 glucose tablets, wait 15 minutes, recheck, and repeat if still low. Then eat a snack or meal.

Causes and emergencies

In people with diabetes, too much insulin or sulfonylurea medicine, skipped meals or intense exercise are common causes. In people without diabetes, fasting, heavy alcohol use, certain medicines, severe liver or kidney disease, hormone deficiencies, reactive hypoglycemia after meals and, rarely, insulin producing tumors can be responsible. Severe hypoglycemia with loss of consciousness or seizure requires glucagon if available and a call to 911. Do not give food or drink to an unconscious person. See a doctor if episodes occur repeatedly.

Based on data from the American Diabetes Association and the NIDDK