Blood sugar testing: Why, when and how
Blood sugar testing: Why, when and how
When you have diabetes, blood sugar testing is the most important thing you can do to feel your best and prevent long-term complications. Consider it an opportunity to take charge of your health.
Know your target range
Your doctor will set your target blood sugar range. For many people who have diabetes, target levels are:
Remember that your target blood sugar range may differ, especially if you're pregnant or you develop diabetes complications. Your target blood sugar range may change as you get older, too. Sometimes reaching your target blood sugar range is a challenge. But the closer you get, the better you'll feel.
When to test your blood sugar
How often you test blood sugar levels depends on many factors, including the type of diabetes you have, your individual diabetes treatment plan, and how well your blood sugar is controlled.
How to test your blood sugar
Blood sugar testing requires a blood sugar monitor. Some monitors are large with easy-to-handle test strips, while others are compact and easier to carry. Some monitors track the time and date of each test, the result and trends over time. If you're unsure which blood sugar monitor is best, ask your doctor or diabetes educator for a recommendation.
To test your blood sugar, follow the instructions that come with your glucose meter. In general, here's how the process works:
Your fingertips contain a lot of nerve endings, so make sure to rotate the sites where you stick your fingers. If you have a newer glucose meter, you'll have the option to test your blood glucose from other sites, such as your forearm or thigh. But check with your doctor or diabetes educator first to find out if alternative site testing is appropriate in your case.
When used correctly, you can count on your blood sugar monitor to provide accurate readings. If you think something's not right, start with the basics:
If you're still not sure what's wrong, do a quality control test according to the manufacturer's instructions and check the owner's manual for other troubleshooting issues. You can bring the monitor to your next doctor appointment as well.
Recording your results
Each time you perform a blood test, log your results. Record the date, time, test results, medication and dosage, and diet and exercise information in a notebook, record book or journal. Better yet, you may be able to download the information to your computer or transfer the information to a mobile device or an online tracking program. The more complete your records are, the more useful they'll be.
This information helps you see how food, physical activity, medication and other factors affect your blood glucose. As patterns occur, you can begin to understand how your daily activities affect your blood sugar levels. This puts you in a better position to manage your diabetes day by day and even hour by hour.
If your blood sugar readings are consistently higher or lower than your target range — or blood sugar extremes don't respond to adjustments in diet or medication — you may need to revise your treatment plan. In some cases, your doctor may suggest changing your diet or including more physical activity in your daily routine. If that's not effective, you may need to take medication or adjust your medication dosage.
Remember, you're not in this alone. Your diabetes treatment team is there to help you manage your diabetes. Work together to make sure you're doing everything you can to prevent diabetes complications.
Last Updated: 2010-03-11
© 1998-2013 Mayo Foundation for Medical Education and Research (MFMER). All rights reserved. A single copy of these materials may be reprinted for noncommercial personal use only. "Mayo," "Mayo Clinic," "MayoClinic.com," "Mayo Clinic Health Information," "Reliable information for a healthier life" and the triple-shield Mayo logo are trademarks of Mayo Foundation for Medical Education and Research.
Terms and conditions of use