What tests can I use to check my blood sugar level?
There are 2 blood tests that can help you manage your diabetes. One of these tests is called an A1C test, which reflects your blood sugar (or blood glucose) control over the past 2-3 months. Testing your A1C level every 3 months is the best way for you and your doctor to understand how well your blood sugar levels are controlled.
Your A1C goal will be determined by your doctor, but it is generally less than 7%.
The other test is called SMBG, or self-monitoring of blood glucose. Using a blood glucose monitor to do SMBG testing can help you improve control of your blood sugar levels. The results you get from an SMBG test can help you make appropriate adjustments to your medicine, diet and/or level of physical activity. Every person who has diabetes should have a blood glucose monitor (also called a home blood sugar meter, a glucometer, or a glucose meter) and know how to use it. Your doctor may prescribe a blood glucose monitor.
The U.S. Food and Drug Administration (FDA) has approved meters that work without pricking your finger. But these meters cannot replace regular glucose meters. They are used to get additional readings between regular testing.
What supplies do I need?
You will need a glucose meter, alcohol pads, sterile finger lancets and sterile test strips. Check with your health insurance plan to see if they will pay for these supplies.
How do I pick a glucose meter?
Check with your health insurance plan to see if they will pay for your glucose meter. If so, your plan may only pay for a certain meter.
If your insurance plan doesn’t pay for glucose meters, ask your doctor which meters he or she recommends. Shop around and compare costs. Consider what features are important to you. For example, some meters are made for people who have poor eyesight. If you want to pay a little more money, you can get a meter that stores the results in its memory. This allows you to compare results from several days at one time. Other meters can be hooked up to your computer to analyze your results.
How do I measure my blood sugar level?
Follow your doctor’s advice and the instructions that come with the glucose meter. In general, you will follow the steps below. Different meters work differently, so be sure to check with your doctor for advice specifically for you.
For someone who has severe diabetes, continuous blood sugar monitoring may be a viable option. With these systems, blood sugar is measured constantly through a sensor placed beneath the skin that transmits information. Some insurance programs are beginning to cover these monitors.
The following are some suggestions on when to do SMBG testing and how to use the results to improve your blood sugar control.
- Wash your hands and dry them well before doing the test.
- Use an alcohol pad to clean the area that you’re going to prick. For most glucose meters, you will prick your fingertip. However, with some meters, you can also use your forearm, thigh or the fleshy part of your hand. Ask your doctor what area you should use with your meter.
- Prick yourself with a sterile lancet to get a drop of blood. (If you prick your fingertip, it may be easier and less painful to prick it on one side, not on the pad.)
- Place the drop of blood on the test strip.
- Follow the instructions for inserting the test strip into your glucose meter.
- The meter will give you a number for your blood sugar level.
What if I can’t get a drop of blood?
If you get blood from your fingertip, try washing your hands in hot water to get the blood flowing. Then dangle your hand below your heart for a minute. Prick your finger quickly and then put your hand back down below your heart. You might also try slowly squeezing the finger from the base to the tip.
How often should I test my blood sugar level?
Your family doctor will recommend how often you should test. Testing times are based on the kind of medicine you take and on how well your blood sugar levels are controlled. You’ll probably need to check your blood sugar more often at first. You’ll also check it more often when you feel sick or stressed, when you change your medicine or if you’re pregnant.
What do I do with the results?
Write down the results in a record book. You can use a small notebook or ask your doctor for a blood testing record book. You may also want to keep track of what you have eaten, when you took medicine or insulin, and how active you have been during the day. This will help you see how these things affect your blood sugar. Talk with your doctor about what is a good range for your blood sugar level and what to do if your blood sugar is not within that range.
What time of day should I test?
Recommendations for the best time of day to test your blood sugar depend on your medicine, mealtimes and blood sugar control. On the chart, your doctor will check the times when you should test your blood sugar. Your doctor may also suggest different goals, depending on your situation.
What do my blood sugar levels tell me?
|Time of Test||Can Be Used to …|
|Fasting blood sugar (FBG) nighttime (3-4 a.m.)||Adjust medicine or long-acting insulin|
|Before a meal||Modify meal or medicine|
|1-2 hours after a meal||Learn how food affects sugar values (often the highest blood sugars of the day*)|
|At bedtime||Adjust diet or medicine (last chance for the next 8 hours)|
*Depends on the size of the meal and the amount of insulin in your medicine
When should I check my blood sugar more frequently?
- If your diabetes medicine changes
- If you begin taking other kinds of medicines
- If you change your diet
- If your exercise routine or activity level changes
- If your level of stress increases
- If you are sick. When you are sick, even without eating, your sugar levels may run high, so testing is important.
Follow your doctor’s testing recommendations during this time. Continue testing more often until you have maintained your SMBG goal values for at least 1 week, or until your doctor advises you that more frequent testing is no longer necessary.
Call your doctor’s office if your blood sugar level is above: _____________
Additional instructions from your doctor:
Check your blood sugar if:
- You have symptoms of low blood sugar (hypoglycemia),which include dizziness, shaking, sweating, chills and confusion
- You have symptoms of high blood sugar (hyperglycemia),which include sleepiness, blurry vision, frequent urination and excessive thirst
- You need to learn how meals, physical activity and medicine affect your blood sugar level
- You have a job in which poor blood sugar control could cause safety problems
- You need help deciding if it is safe to drive or perform other tasks that require concentration if you are taking insulin or have had hypoglycemia in the past
Tips on blood sugar testing
- Pay attention to expiration dates for test strips.
- Use a big enough drop of blood.
- Be sure your meter is set correctly.
- Keep your meter clean.
- Check the batteries of your meter.
- Follow the instructions for the test carefully.
- Write down the results and show them to your doctor.
Portions of this article were developed as part of an educational program made possible by an unrestricted educational grant from LifeScan, Inc., makers of OneTouch Blood Glucose Meters.
Portions of this article were developed by the American Academy of Family Physicians in cooperation with the American Diabetes Association.
Copyright © American Academy of Family Physicians
This information provides a general overview and may not apply to everyone. Talk to your family doctor to find out if this information applies to you and to get more information on this subject.