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Treating Low Blood Sugar

Topic Overview

Review the symptoms of low blood sugar if you have diabetes or some other health condition that can cause low blood sugar. Symptoms of low blood sugar include sweating, blurred vision, hunger and confusion. Know your early symptoms. You may not always have the same symptoms, or any symptoms at all.

Tell your partner, co-workers, and friends how to treat your low blood sugar, in case you're too weak or confused to treat it yourself. If your child has diabetes, give this information to teachers, coaches, and other school or child care staff.

When you have low blood sugar, remember:

  • Check your blood sugar if you think it may be low, below 4.0 millimoles per litre (mmol/L).
  • Eat quick-sugar foods. If you're at home, you probably already have something close at hand that contains sugar, such as glucose or dextrose tablets, table sugar or fruit juice. Carry some quick-sugar food or glucose or dextrose tablets with you when you are away from home.
  • Wait about 15 minutes after eating and check your blood sugar level again. If your blood sugar is still below 4.0 mmol/L, eat another quick-sugar food. Repeat every 15 minutes until your blood sugar is in a safe target range, 4.0 mmol/L or higher. When your blood sugar returns to your target range, eat a small snack if your next planned meal or snack is more than 1 hour away. If it's mealtime, eat your meal as planned.
  • Don't drive if your blood sugar is lower than 5.0 mmol/L. Wait at least 40 minutes after your low blood sugar is treated and you're in a safe range before driving.
  • If your blood sugar continues to be below 4.0 mmol/L or you are getting more sleepy and less alert, call 911 or other emergency services immediately. If possible, have someone stay with you until your blood sugar is above 4.0 mmol/L or until emergency help arrives.

Information for family, friends, and co-workers

Use the following information to help someone who can't follow instructions or is too weak or confused to treat their low blood sugar.

If the person is taking medicine that can continue to cause low blood sugar, stay with the person for a few hours after their blood sugar level has returned to the target range.

  • If the person can't follow instructions or if the person is unconscious (passed out):
    • Do not try to give the person foods or liquids, because they could be inhaled (breathed into the lungs). This is dangerous.
    • Prepare a shot of glucagon if one is available, and give the person the shot. Follow the directions that come with the glucagon medicine.
    • A glucagon shot may not work as well if the person has had 2 or more drinks with alcohol in the last few hours, if they have been fasting for a few hours, or if the person has a serious liver disease.
    • After you give the glucagon shot, immediately call 911 for emergency care.
    • Turn the person on their side, and make sure the airway is not blocked.
    • If emergency help has not arrived within 5 minutes and the person is unconscious, give another glucagon shot, if you have one.
    • Stay with the person until emergency help comes.
  • If the person can follow instructions:
    • Give the person a quick-sugar food.
    • Wait about 15 minutes and check the person's blood sugar again, if a meter is available.
    • If their blood sugar is still below 4.0 mmol/L, they should eat another quick-sugar food. Repeat every 15 minutes until their blood sugar is in a safe target range, above 4.0 mmol/L. When their blood sugar returns to their target range, they should eat a small snack if their next planned meal or snack is more than 1 hour away.
    • If the person becomes more sleepy or lethargic, call 911 or other emergency services.
    • Stay with the person until his or her blood sugar level is 4.0 mmol/L or higher or until emergency help comes.


Other Works Consulted

  • Seaquist ER, et al. (2013). Hypoglycemia and diabetes: A report of a workgroup of the American Diabetes Association and The Endocrine Society. Diabetes Care, 36(5): 1384–1395. Available online:


Adaptation Date: 8/19/2021

Adapted By: Alberta Health Services

Adaptation Reviewed By: Alberta Health Services

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