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How to Check Your Blood Sugar

Tips For Managing Your Diabetes


Updated May 02, 2011

Written or reviewed by a board-certified physician. See About.com's Medical Review Board.

How to Check Your Blood Sugar

Frequent blood sugar testing greatly helps to manage your diabetes.

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Why is checking blood sugar important?

Checking your blood sugar (glucose) is the only way you can confidently know what your blood sugar level is at any given time. Fortunately, we now have many small, pocket-sized blood glucose monitoring devices that require only a very small blood sample. These battery-operated meters can usually return a result within a few seconds.

It is a myth that you can accurately predict your glucose level based on how you feel. Regular testing helps you identify high and low levels before serious health problems could develop. When you test your blood sugar on a regular basis, it helps you and your doctor assess how well you are balancing your insulin therapy, meal planning, stress and exercise to manage your diabetes.

How do I check my blood sugar?

  1. Wash and thoroughly dry your hands before touching the glucose test strips. Unclean or wet hands can give you inaccurate glucose readings.
  2. Insert the test strip into your glucose meter. Make sure the glucose strips are compatible with the type of meter you are using and that they have not expired. Expired strips can give inaccurate results.
  3. Firmly press the open end of your lancing device against your skin and push the button on the lancing device to release the action of the lancet. Most people prefer to use their fingers for testing, although most meters will accept blood samples from alternate testing sites. If using the finger for your blood sample, it is usually less painful to lance the side of the finger versus the finger tip.
  4. Gently squeeze or massage your finger until a drop of blood forms. The newer meters require a very small sample so it is not difficult to get the proper amount of blood.
  5. Touch the drop of blood at the appropriate place designated on the strip. When the meter has a sufficient amount of blood for the test, it will automatically analyze it.
  6. Your result will appear on the meter’s display screen. Nearly all meters produce glucose results within 10 seconds.

When should I check my blood sugar?

When you have type 1 diabetes, it is necessary to check your blood sugar often so you can balance your insulin, food, and exercise to maintain your blood sugar as close to normal as possible. The most common times to test your blood on a daily basis are:

  • In the morning before breakfast
  • 1-2 hours after breakfast
  • Before lunch
  • 1-2 hours after lunch
  • Before dinner
  • 1-2 hours after dinner
  • Before bedtime
  • And possibly in the middle of the night (around 3 a.m.) if you are prone to blood sugar lows at night

Your doctor may recommend blood sugar testing more or less frequently than those times mentioned.

But regardless of how often you test daily, there are times when you will want to check your blood sugar more often than usual:

  • When you are ill. Your blood sugar levels may be higher than normal.
  • When you are more physically active than usual. Activity, especially if it is strenuous, tends to lower blood sugar.
  • When you are under significant stress. The stress response tends to raise your blood sugar.
  • When you are pregnant. You will want to work closely with your doctor to maintain good blood sugar control during pregnancy for your and your baby’s health.
  • When there are changes to your diabetes management program, such as a new insulin schedule, meal plan or exercise routine.
  • When you are taking new medications. Certain medications, such as steroids, can affect blood sugar levels.
  • When you suspect your blood glucose is low. If you are ever in doubt, always check your blood to prevent a low blood sugar (hypoglycemic) reaction.


Joslin Diabetes Center. " When to test blood glucose."

Joslin Diabetes Center. "Little things that can have a big impact on your blood reading reading."

American Diabetes Association. "Checking your blood glucose."

  1. About.com
  2. Health
  3. Type 1 Diabetes
  4. Blood Sugar Monitoring
  5. Checking Your Blood Sugar – How to Check Your Blood Sugar

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