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Diabetes in Children: Preventing High Blood Sugar


High blood sugar occurs when the sugar (glucose) level in the blood rises above normal. It is also called hyperglycemia. If your child has diabetes, high blood sugar may be caused by missing a dose of diabetes medicine or insulin. It may also be caused by eating too much, skipping exercise, or being ill or stressed. Fast growth during the teen years can also make it harder to keep your child's blood sugar levels in his or her target range.

Unlike low blood sugar, high blood sugar usually happens slowly over hours or days. But it can also happen quickly (in just a few hours) if your child eats a large meal or misses an insulin dose.

Blood sugar levels above the target range may make a person feel tired and thirsty. If your child's blood sugar level stays higher than normal, his or her body will adjust to that level. If your child's blood sugar keeps rising, the kidneys will make more urine and your child can get dehydrated. Severe dehydration can be life-threatening. Over time, high blood sugar can damage the eyes, heart, kidneys, blood vessels, and nerves.

Watch for symptoms of high blood sugar. Symptoms include feeling very tired or thirsty and urinating more often than usual. As long as you or your child notices the symptoms, you will probably have time to treat high blood sugar so that it doesn't become an emergency. Three steps can help you prevent high blood sugar problems:

  • Test your child's blood sugar often, especially if your child is sick or when he or she is not following a normal routine. A child may not have symptoms of high blood sugar. Testing lets you see when your child's blood sugar is above his or her target range, even if your child doesn't have symptoms.
  • Call the doctor if your child often has high blood sugar levels or if the blood sugar level is often staying above his or her target range. The medicine or insulin dosage may need to be adjusted or changed.
  • Encourage your child to drink extra water or drinks that don't have caffeine or sugar. Getting more fluids can help prevent dehydration.

How can you prevent high blood sugar?

Treat infections early

Infections that aren't treated, such as urinary tract infections and skin infections, can raise your child's risk of a high blood sugar emergency.

Be prepared

  • Know the symptoms of high blood sugar. Post them in a place where you and your child can see them often, such as on your refrigerator door. Add any symptoms your child has had that are not on the list. Make sure other people know the symptoms. Teach them what to do in an emergency. Symptoms of high blood sugar include feeling very thirsty, feeling very tired, and urinating more than usual.
  • Check your child's blood sugar at home often, especially when your child is sick or not following his or her normal routine. Testing your child's blood sugar at home will help you know when it is high, even if your child doesn't notice symptoms.
  • Teach others involved in your child's care how to check blood sugar. Keep instructions for using the blood sugar meter with the meter. That way someone else could test your child's blood sugar if needed.
  • Have your child wear medical identification at all times. One example is a medical alert bracelet. This is very important in case your child is too sick or injured to speak.
  • If your child takes insulin, do a test for ketones when blood sugar is high.
  • Make a plan. Usually people who take insulin need to take extra fast-acting insulin when their blood sugar levels are high. Talk with your child's doctor about how much your child needs to take. This depends on his or her blood sugar level (sliding scale).
  • Give your child's medicines as prescribed. Don't skip the medicines for diabetes or insulin shots without first talking with your doctor.

Treat high blood sugar early

The best way to prevent high blood sugar emergencies is to treat high blood sugar as soon as your child has symptoms or when his or her blood sugar is well above the target range (for example, 11.0 mmol/L or higher).

  • Follow the steps for dealing with high blood sugar. Post the steps in a handy place at home. Make sure other people know what to do if your child is unable to treat high blood sugar.
  • Keep a record. Write down your child's symptoms and how you treated them. And take the record with you when you see your child's doctor. Use a blood sugar record .
  • Let your child's doctor know if your child is having high blood sugar problems. The medicine for diabetes may need to be adjusted or changed. If your child takes insulin, the dose may need to be increased.

Offer plenty of liquids

If your child's blood sugar levels are above his or her target range, offer extra liquids. This helps to replace the fluids lost through the kidneys. Water and sugar-free drinks are best. Avoid caffeinated drinks, regular soda pop, fruit juice, and other liquids that have a lot of sugar.


Other Works Consulted

  • Canadian Diabetes Association Clinical Practice Guidelines Expert Committee (2013). Canadian Diabetes Association 2013 clinical practice guidelines for the prevention and management of diabetes in Canada. Canadian Journal of Diabetes, 37(Suppl 1). Also available online:


Current as of:
August 31, 2020

Author: Healthwise Staff
Medical Review:
John Pope MD - Pediatrics
Adam Husney MD - Family Medicine
Kathleen Romito MD - Family Medicine
Stephen LaFranchi MD - Pediatrics, Pediatric Endocrinology