Diabetes Health Center

Low blood sugar, also called hypoglycemia, occurs when the sugar (glucose) level in the blood drops below what the body needs to function normally.

Key points

• Not all oral medicines for diabetes cause low blood sugar. Usually, these medicines cause blood sugar to drop low enough to cause only mild symptoms, such as sweating, shakiness, and hunger. If your child eats something that contains sugar, his or her blood sugar level will rise. But if your child doesn't eat something that contains sugar, his or her blood sugar may continue to drop to a very low level. Symptoms of severe hypoglycemia can include disorientation, confusion, combativeness, and loss of consciousness.
• Taking too many doses of oral medicine for diabetes in one day, not eating enough food, or doing strenuous exercise can cause your child's blood sugar level to drop below the target range. Children who take insulin are also at risk for low blood sugar. If your child's blood sugar drops very low, he or she could go into a coma and possibly die.
• To prevent serious problems from low blood sugar:
  • Test your child's blood sugar often. Or have your child test his or her own blood sugar.
  • Be alert to the early signs of low blood sugar, such as sweating, shakiness, hunger, blurred vision, and dizziness.
  • Keep some hard candy, raisins, or other quick sugar foods with your child at all times. Have your child eat some at the first sign of low blood sugar.
  • Teach your child's caregivers, teachers, and coaches what to do if your child has low blood sugar.

More information about children with diabetes can be found in these topics:

• Type 1 Diabetes: Children Living With the Disease
• Type 2 Diabetes in Children

Low blood sugar (hypoglycemia) means that the level of sugar, or glucose, in your child's blood has dropped below what his or her body needs to function normally. When your child's blood sugar level drops below 70 milligrams per deciliter (mg/dL), he or she most likely will have symptoms, such as feeling tired, weak, or shaky. A very low blood sugar level (below 20 mg/dL) can develop quickly and is an emergency requiring immediate care.

The sulfonylureas-such as glipizide (Glucotrol), glimepiride (Amaryl), and glyburide (DiaBeta)-and insulin injections can cause low blood sugar levels. Low levels from sulfonylurea medicines usually cause only symptoms of mild low blood sugar, unless a child also takes insulin.

Sometimes people with diabetes develop low blood sugar levels during the night. This is not likely to happen unless your child takes insulin injections. If it does happen, your child may wake up in a cold sweat and feel weak. But your child may sleep through it because his or her body uses stored sugar to raise the blood sugar back to a target level. If this happens, your child most likely will wake up in the morning with a headache and possibly high blood sugar.

What causes low blood sugar?

Low blood sugar levels can occur if your child:

• Takes too many doses of a sulfonylurea in one day or takes doses too close together.
• Continues to take the full dose of sulfonylurea but does not eat his or her usual amount of food.
• Takes insulin and does not eat his or her usual amount of food.
• Exercises strenuously without eating enough.

Your child may have symptoms of low blood sugar if his or her blood sugar drops to a level lower than usual. For example, if your child's level has been in the 300s for a week and it drops suddenly to 100, he or she may have symptoms of low blood sugar. After your child has had diabetes for many years, he or she may not have symptoms of hypoglycemia until the blood sugar level is very low. This is called hypoglycemia unawareness.

Very low blood sugar levels usually do not occur in children who take oral medicines other than sulfonylureas. These medicines include metformin (Glucophage), acarbose (Precose), rosiglitazone (Avandia), and pioglitazone (Actos). Very low blood sugar more commonly occurs in children who take insulin injections.

If your child's blood sugar drops below 40 mg/dL, his or her brain may receive too little sugar to work properly, and judgment and muscle coordination will be affected. Your child may not recognize low blood sugar and may not be aware that he or she needs to eat. You or someone else may have to help your child eat or drink something to raise the blood sugar level.

If your child's blood sugar level continues to drop below 20 mg/dL, he or she can lose consciousness and possibly die.

A low blood sugar level may soon recur, even though it has been treated. For example, some sulfonylurea medicines can continue to lower blood sugar levels for up to 24 hours. If your child's blood sugar level drops to a low level, check it frequently for some time after the low level has been treated.

Here are some ways you can manage a low blood sugar emergency.

Be prepared

• Keep some quick-sugar food with your child at all times. It can raise your child's blood sugar level 30 mg/dL in 15 minutes.
• Know the symptoms of low blood sugar. Post a list of these symptoms where you and your child will see it often. Have your child carry a copy at all times. Add any symptoms you have noticed in your child that are not on the list. The child may not always have the same symptoms.
• Have your child wear medical identification, such as a medical alert bracelet . People will know that your child has diabetes and can get help in case your child's blood sugar drops very low. See the Where to Go From Here section below to learn where to purchase medical identification.
• Teach your child's caregivers how to check blood sugar. Have instructions with the blood sugar meter.
• Post the instructions for emergency care for a child with low blood sugar in a convenient place at home and at school.

Treat low blood sugar early

Check your child's blood sugar if you think it may be low, even if you don't see any symptoms. If your child's blood sugar level is below 70 mg/dL and:

• If your child is alert:
  • Give him or her 4 oz of liquid (juice or soda pop) from the list of quick-sugar foods or glucose tabs or gel if available.
  • Wait 10 to 15 minutes.
  • Offer your child more quick-sugar food if he or she is feeling better but still has some symptoms of low blood sugar.
  • Check your child's blood sugar level using his or her blood sugar (glucose) meter if available.
  • Stay with your child until his or her blood sugar level is 70 milligrams per deciliter (mg/dL) or higher.
  • Offer your child a snack (such as cheese and crackers or half of a sandwich).
  • If your child becomes more sleepy or seems to have no energy, call 911 or other emergency services.
• If your child is not alert, follow the appropriate guidelines in Emergency Care for a Child With Low Blood Sugar.

After the episode

• Write down your child's symptoms and what you did. Use the low blood sugar level record(What is a PDF document?).
• Let your child's doctor know if your child is having frequent low blood sugar problems. His or her medicine may need to be adjusted or changed.

Now that you have read this information, you and your child are ready to start dealing with low blood sugar levels effectively.

Talk with your child's doctor

If you have questions about this information, take it with you and discuss it with the doctor. You may want to mark areas or make notes in the margins where you have questions.

Medical identification jewelry can be purchased at most pharmacies. Talk with your doctor or contact the local American Diabetes Association about other places to purchase medical identification.

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