Lifespan's A - Z Health Information Library

Blood glucose monitoring is a measurement of glucose (sugar) in the blood. The test can be done at any time on a portable machine. It can be a self-test for a person with diabetes.

The finger is pricked and a drop of blood is put on a special strip, which uses a chemical substance to determine the amount of glucose in the blood. The meter then reads the strip and displays the results as a number on a digital display. Newer monitors can use blood from other areas of the body besides the fingers, reducing discomfort.

Have all test items within reach before starting -- timing is important. Clean the area with soap and water or an alcohol swab. The area needs to be completely dry before pricking.

There is a sharp prick.

The test allows the person with diabetes to carefully monitor blood glucose levels, to assure that they are within the normal range. The individual can then respond quickly to high or low blood sugar levels (hyperglycemia or hypoglycemia) with appropriate intervention. Such intervention includes adjusting diet, exercise, and insulin dose as instructed by your physician.

This test can also be a screening test for blood glucose levels.

Range from before-meal glucose levels of 90 to 130 milligrams per deciliter (mg/dL); after-meal values of 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.

If levels are too low, the person is in a state of hypoglycemia. Food should be eaten, and the individual may need to alter the next insulin dose and possibly future insulin doses as well.

If levels are too high, the person is hyperglycemic, and may need additional insulin.

Additional conditions under which the test may be performed:

• Type 1 diabetes
• Type 2 diabetes
• Hypoglycemia

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.

Abnormal results, particularly in a person not known to have diabetes, may indicate a need to obtain a fasting blood glucose or a glucose tolerance test. Consult the health care provider.