How Long Do You Have to Fast for a Glucose Test?

Glucose tests are performed to test for hypoglycemia or hyperglycemia, which serve as possible indicators of diabetes. Diabetes is a patient's inability to regulate the levels of sugar and insulin. Performing a glucose test is an important step in diagnosing this condition.

A Patient's Preparation

• A patient can take a glucose test at any random time or following an 8- to 10-hour fast. The American Diabetes Association suggests taking the test after fasting, and also taking a second the test on a different day after the initial test. This increases the accuracy of the diabetes diagnosis. After the patient has fasted for 8 to 10 hours, the doctor may test the patient's glucose level, and then give the patient a quick drink of glucose to test how the system reacts. This test is called an Oral Glucose Tolerance Test (OGTT). The fast in preparation is an important step in assuring the accuracy of the screening.