Check your blood sugar level as often as instructed by your health care provider. Write down the results. This will tell you how well you are managing your diabetes.
Not everyone with diabetes needs to check their blood sugar every day. Some people need to check it many times a day.
Checking blood sugar helps many people stay on track with their nutrition and activity plans.
Check Your Blood Sugar Often
Usual times to test your blood sugar are before meals and at bedtime. Sometimes your provider will ask you to check your blood sugar two hours after a meal. Ask your provider when you should check your blood sugar.
Other times to check your blood sugar may be:
If you are having symptoms of low blood sugar (hypoglycemia)
After you eat out, especially if you have eaten foods you do not normally eat
If you feel sick
Before or after you exercise
If you have been under a lot of stress
If you eat too much or skip meals or snacks
If you are taking new medicines, took too much insulin or diabetes medicine by mistake, or took your medicine at the wrong time
If your blood sugar has been higher or lower than normal
If you are drinking alcohol
How to Prepare for the Test
Have all test items within reach before starting. Timing is important. Clean the needle prick area with soap and water. Completely dry the skin before pricking.
How the Test is Done
Most glucose meters have:
Small needles (lancets) that fit into a spring-loaded plastic device
A logbook for recording your numbers
There are many kinds of meters. But they all work the same way.
You can buy a testing kit from a pharmacy without a prescription. Your provider can help you choose the right one for you. They can also help you set up the meter and teach you how to use it.
To do the test, prick your finger with the needle and place a drop of blood on a special strip. This strip measures how much glucose is in your blood. Some monitors use blood from areas of the body other than the fingers, reducing discomfort. The meter shows your blood sugar results as a number on a digital display. If your vision is poor, talking glucose meters are available so that you do not have to read the numbers.
Keep a Record
Keep a record for yourself and your health care provider. This will be a big help if you are having problems controlling your diabetes. It will also tell you what you did when you were able to control your diabetes. To get the most help with controlling your blood sugar, write down:
The time of day
Your blood sugar level
The amount of carbohydrates you ate
The type and dose of your diabetes medicine
The type of any exercise you do and how long you exercise for
Anything unusual, such as stress, eating different foods, or being sick
Blood sugar meters can store hundreds of readings. Most types of meters can save readings to your computer or smart phone. This makes it easy to look back at your record and see where you may have had problems.
Always bring your meter when you visit your provider. You and your provider can look at your blood sugar patterns together and make adjustments to your medicines, if needed.
You and your provider should set a target goal for your blood sugar level for different times of the day. If your blood sugar is higher than your goals for 3 straight days and you do not know why, call your provider.
Buse JB, Polonsky KS, Burant C. Type 2 diabetes mellitus. In: Melmed S, Polonsky KS, Larsen PR, Kronenberg HM, eds. Williams Textbook of Endocrinology. 12th ed. Philadelphia, PA: Elsevier Saunders; 2011:chap 31.
Eisenbarth GS, Buse JB. Type 1 diabetes mellitus. In: Melmed S, Polonsky KS, Larsen PR, Kronenberg HM, eds. Williams Textbook of Endocrinology. 12th ed. Philadelphia, PA: Elsevier Saunders; 2011:chap 32.
Brent Wisse, MD, Associate Professor of Medicine, Division of Metabolism, Endocrinology & Nutrition, University of Washington School of Medicine, Seattle, WA. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.