Health

If you suddenly experience symptoms of increased thirst, frequent urination, or unexplained weight loss, diabetes may be the cause. To confirm the diagnosis, a fasting plasma glucose test or a casual plasma glucose test will be performed.

The preferred method of diagnosing diabetes is the fasting plasma glucose (FPG) test because it is easy to administer, convenient for patients, and less expensive than other tests (according to the American Diabetes Association). The FPG measures your blood glucose level after you have fasted or not eaten for 10 to 12 hours. Normal fasting blood glucose is between 70 and 100 mg/dl for people who do not have diabetes. The standard diagnosis of diabetes is made when two blood tests show that your fasting blood glucose level is greater than or equal to 126 mg/dl.

Some people have a normal fasting blood glucose reading, but their blood glucose rises rapidly as they eat. These people may have glucose intolerance. If their blood glucose levels are high enough, they may be considered to have diabetes.

In a casual plasma glucose test, blood glucose is tested without regard to the time since the person's last meal. A glucose level greater than 200 mg/dl may indicate diabetes, especially if the test is repeated at a later time and indicates similar results.

The oral glucose tolerance test is another method used to detect diabetes, but is not routinely performed except during pregnancy.

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