Tests Used for Diagnosing Diabetes

People with diabetes have unusually high blood glucose levels either because not enough insulin is produced (Type 1) or the insulin is not used right in the body (Type 2). Insulin is a hormone that helps cells absorb glucose. Various tests are used to measure blood glucose levels.

 

A Fasting Plasma Glucose (FPG) test requires patients to not eat for a minimum of 8 hours before having their blood drawn and analyzed. A healthy blood glucose level for this test will be below 99mg/dL. If your level is between 100 and 125 mg/dL, you may have what is called "pre-diabetes", which means if you don't keep your glucose levels under control with diet and exercise, you are going to end up with diabetes.

If your level is above 126 mg/dL, you have a serious case of diabetes that will require further testing so that you can get diagnosed and be treated. Usually, an Oral Glucose Tolerance Test  (OGTT) is done in this situation. This requires you to fast and then drink a high glucose liquid before a blood test. The blood test occurs after the liquid has been consumed and then several times after that at intervals. After two hours, your blood glucose level should be below 139 mg/dL. Your body should release insulin to help cells absorb glucose. If your glucose levels are between 140 and 199 mg/dL, this process is not working properly, which could indicate pre-diabetes. Levels above 200 mg/dL indicate that you have diabetes.

If your glucose levels indicate diabetes is present, your doctor will probably repeat the testing to make sure nothing else (steroids, pregnancy, diuretics, etc.) is affecting the results and causing them to appear to be so high before he starts you on a treatment plan.

Gestational diabetes occurs in about 3% of pregnant women and is detected using the OGTT test. The blood glucose levels are checked four different times. Another option is the Random Plasma Glucose (RPG) test, which does not require fasting. Glucose levels with the RPG test above 200 mg/dL indicate diabetes may be present. The symptoms of diabetes include urinating frequently and feeling thirsty all the time.

One test is never enough to diagnose diabetes. Diabetes is a serious illness that can be managed easily by making some healthy changes in your life in most cases but several tests are required before any treatments are started.