Blood glucose test

A diagnosis of diabetes is based on the patient's blood glucose level.

There are three different tests for blood glucose level:


 * Casual plasma glucose -- taken when the patient has been eating normally. A diagnosis of diabetes requires a casual plasma glucose level of 200 mg/dL or higher on at least 2 separate occasions.


 * Fasting plasma glucose -- taken when the patient has been fasting for twelve hours. A diagnosis of diabetes requires a fasting plasma glucose level of 126 mg/dL or higher on 2 occasions.


 * Oral glucose tolerance test -- the patient is given 75g of glucose to ingest orally. A diagnosis of diabetes requires a oral glucose tolerance level of 200 mg/dL or higher.

As a contrast, the average, non-diabetic fasting plasma glucose level is lower than 100 mg/dL.