Blood glucose monitoring
Blood glucose monitoring refers to the ongoing measurement of blood sugar (glucose). Monitoring can be done at any time using a portable device called a glucometer.
Home glucose monitoring; Self monitoring of blood glucose
How the test is performed
The traditional glucose meter comes with test strips, small needles called lancets, and a logbook for recording your numbers. There are many different kinds of these meters, but they all work essentially the same way.
A complete testing kit can be purchased from a pharmacy without a prescription. Your doctor or nurse can help you choose the equipment that's right for you, help you set it up, and teach you how to use it.
You will prick your finger with the lancet and place a drop of blood on a special strip. This strip uses a chemical substance to determine the amount of glucose in the blood. (Newer monitors can use blood from other areas of the body besides the fingers, reducing discomfort.) The meter displays your blood sugar results as a number on a digital display.
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 or an alcohol swab. Completely dry the skin before pricking.
How the test will feel
There is a sharp prick.
Why the test is performed
This test reveals your blood sugar level.
If you have diabetes, you can use it to carefully monitor your blood sugar levels at home. Regularly checking your blood sugar level is one of the most important steps you can take in managing the disease. It provides your doctor with important information regarding the control of your blood sugar.
When you keep track of your blood sugar you will:
- Start to see patterns that will help you plan meals, activities, and what time of day to take your medications
- Learn how certain foods affect your blood sugar levels
- See how exercise can improve your numbers
Testing allows you to respond quickly to high blood sugar (hyperglycemia) or low blood sugar (hypoglycemia). This might include diet adjustments, exercise, and insulin (as instructed by your health care provider).
Your doctor may order a blood sugar test to screen for diabetes. For more information, see blood glucose test.
- Before meals: 70 - 130 milligrams per deciliter (mg/dL)
- After meals: Less than 180 mg/dL
Values can vary depending on physical activity, meals, and insulin administration. Normal value ranges may vary slightly among different laboratories. Talk to your doctor about the meaning of your specific test results.
The examples above show the common measurements for results for these tests. Some laboratories use different measurements or may test different specimens.
What abnormal results mean
Low levels indicate hypoglycemia. Have something to eat. You may need to change the next insulin dose, and possibly future insulin doses as well.
If levels are too high, this indicates hyperglycemia. You may need additional insulin.
What the risks are
There is a slight chance of infection at the puncture site. A small amount of bleeding may occur after the puncture.
The correct procedure must be followed or the results will not be accurate.
American Diabetes Association. Standards of medical care in diabetes--2010. Diabetes Care. 2010 Jan;33 Suppl 1:S11-61.
Last reviewed 4/19/2010 by Ari S. Eckman, MD, Division of Endocrinology and Metabolism, Johns Hopkins School of Medicine, Baltimore, MD. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.
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