Keeping blood glucose (sugar) levels in a healthy range can be challenging.

Knowing and understanding the symptoms of high and low blood sugar is very important for people living with diabetes, as well as their friends and family members.

What is low blood sugar?

When the amount of sugar in your blood has dropped below your target range (less than four mmol/L), it is called low blood sugar or hypoglycemia.

What are the signs of a low blood sugar level?

You may feel:

  • Shaky, light-headed, nauseated
  • Nervous, irritable, anxious
  • Confused, unable to concentrate
  • Hungry
  • Your heart rate is faster
  • Sweaty, headachy
  • Weak, drowsy
  • A numbness or tingling in your tongue or lips

Very low blood sugar can make you:

  • Confused and disoriented
  • Lose consciousness
  • Have a seizure

Make sure you always wear your MedicAlert® identification, and talk to your doctor or diabetes educator about prevention and emergency treatment for severe low blood sugar.

What causes a low blood sugar level (hypoglycemia)?

Low blood sugar may be caused by:

  • More physical activity than usual
  • Not eating on time
  • Eating less than you should have
  • Taking too much medication
  • The effects of drinking alcohol

How do I treat low blood sugar?

If you are experiencing the signs of a low blood sugar level, check your blood sugar immediately. If you don’t have your meter with you, treat the symptoms anyway. It is better to be safe. Low blood sugar can happen quickly, so it is important to treat it right away. If your blood sugar drops very low, you may need help from another person.

Step one: Eat or drink a fast-acting carbohydrate (15 grams):

  • 15 grams of glucose in the form of glucose tablets 
  • 15 millilitres (one tablespoon) or three packets of sugar dissolved in water
  • 150 millilitres (⅔ cup) of juice or regular soft drink
  • Six LifeSavers® (one = 2.5 grams of carbohydrate)
  • 15 millilitres (one tablespoon) of honey (do not use for children less than one year old)

Step two: After treating the symptoms, wait 15 minutes, then check your blood sugar again. If it is still low:

  • Treat again; wait 15 minutes, and check your blood sugar again. Repeat these steps until your blood sugar is above 4 mmol/L.

Step three: When your blood sugar is above 4 mmol/L:

  • If your next meal is more than one hour away, or you are going to be active, eat a snack, such as half of a sandwich or cheese and crackers (something with 15 grams of carbohydrate and a protein source)
  • Wait 40 minutes after treating a low blood sugar before driving

Think about why your blood sugar went low and make the necessary changes to avoid low blood sugar again.

What is high blood sugar?

When your fasting blood sugar is at or above 11 mmol/L, you may:

  • Be thirsty
  • Urinate more often than usual, especially during the night
  • Be tired

What causes high blood sugar levels (hyperglycemia)?

High blood sugar can result when food, activity and medications are not balanced. High blood sugar may happen when you are sick or under stress.

What do I do if I have high blood sugar?

Follow the treatment recommended by your doctor, diabetes educator or other member of your health-care team. If this happens often, you may need to call or see your doctor to:

  • Adjust your meal plan
  • Adjust your physical activity
  • Adjust your medication and/or insulin

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