Definition
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.
Alternative Names
Glucose monitoring; Random glucose; Glucose - random; Serum glucose - random; Self monitoring of blood glucoseHow the test is performed
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.
How to prepare for the test
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.
How the test will feel
There is a sharp prick.
Why the test is performed
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.
Normal Values
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.
What abnormal results mean
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
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.
Special considerations
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.
| • | Glucose test |
| • | Diabetes |
| • | Hypoglycemia |
Reviewed By: David Juan, MD, Specializing in Endocrinology Issues, Good Hand Medical Center and Alperin Medical Clinics, Santa Clara, CA. Review provided by VeriMed Healthcare Network.

