Chapter 10: Low Blood Glucose (Hypoglycemia)

Low Blood Glucose (Hypoglycemia)

Hypoglycemia (said like: hi poe glie SEE mee ah), or low blood glucose, is the most common problem with insulin therapy. Low blood glucose is when the blood glucose falls below 70 mg/dl. Hypoglycemia can happen very quickly.

What causes low blood glucose?

  • Not enough carbohydrates eaten
  • Too much insulin given
  • More exercise than normal

How do I prevent low blood glucose?

  • The best way to prevent low blood glucose is to take insulin based on the amount of carbohydrates you are eating, your blood glucose level, and your planned activity level.
  • Plan ahead if you know you will be doing more activity than normal.
  • Test your blood glucose regularly.

What do I need to be ready for a low blood glucose?

  • Know YOUR signs of low blood glucose. Your family and friends will also need to learn your signs of low blood glucose so they can help you treat it.
  • Always keep some form of sugar with you.
  • Always keep your blood glucose meter with you.
  • Always have a Glucagon Emergency Kit (see page 49).
  • Always wear a medical necklace or bracelet, or carry a medical ID card in your wallet.

What are the signs of low blood glucose?

Because sugar (glucose) is the main fuel for the brain, a sudden drop in the glucose level can cause the following symptoms:
Early Signs Late Signs Signs While Sleeping
  • Shakiness
  • Nervousness
  • Stomach ache
  • Weakness
  • Blurry vision
  • Dizziness
  • Pale skin
  • Sweating
  • Headache
  • Personality change
  • Seizures
  • Confusion
  • Irritability, crankiness
  • Unconsciousness
  • Nightmares
  • Waking up suddenly
  • Sweating; wet clothes or sheets
  • Fast heart beat
  • Can’t fall back to sleep; restless

How do I treat low blood glucose with the 15/15 Rule?

Step 1: Stop what you are doing if you have any signs of low blood glucose, and check your blood glucose. You may have to:
  • Let your coach know you need a break.
  • Leave class in the middle of a lesson and go to the nurse’s office.
Step 2: Read the results.
  • For children up to 1 year old, treat blood glucose of 90 or below.
  • For children 1 to 4 years old, treat a blood glucose of 80 or below.
  • For children 5 years old or more, treat a blood glucose of 70 or below.
Step 3: Treat the low blood glucose with a 15 gram carbohydrate snack that works fast (Picture 1). This is called a fast-acting carbohydrate. If your blood glucose is low, your body needs sugar quickly. If these symptoms are not treated, seizures and/or unconsciousness can happen.
Eat a 15 gram fast-acting carbohydrate. One of the following would be a good choice:
  • 4 ounces of 100% fruit juice
  • 3 to 4 glucose tablets
  • 1 tube of glucose gel
  • Candy, like Skittles or gummy bears.
Do not use candy bars or other candy that has fat.


Picture 1: Always carry some kind of glucose with you, like glucose tablets or fruit juice.

Step 4: Check your blood glucose again in 15 minutes. Do this even if you feel better.
  • If your blood glucose is still below target range (70 - 80 mg/dl), repeat steps 3 and 4.
  • If your blood glucose is above target range (70-80 mg/dl) and it is more than 1 hour until your next meal, eat another 15 gram carbohydrate snack with protein. This can be any of the following:
    • Peanut butter or cheese and crackers
    • Half of a sandwich
    • Granola bar
    • One glass of milk

What do I do about low blood glucose at nighttime?

It is a good idea to keep small boxes or cans of juice at your bedside to treat low blood glucose in the middle of the night. Make sure to follow up with a snack of 15 grams of complex carbohydrate and protein before going back to bed. Cheese and crackers are a good choice. You do not need to eat a full meal.
Important to Remember
  • Remember, if blood glucose is below target before a meal, treat before you eat. When blood glucose is above 70 mg/dl, take your insulin before you eat a meal or another snack.
  • If you have signs of low blood glucose, but cannot test your blood, you should treat for low blood glucose anyway. Use the 15/15 Rule, giving yourself 15 grams of carbohydrate and checking your blood glucose in 15 minutes.
  • Have a signal for your teacher or your coach that lets them know you are having signs of low blood glucose.

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