A fasting blood glucose test is a blood test performed after eight hours of fasting. This test is often performed as part of a diabetes management plan or as a diagnostic test when diabetes is suspected. Blood glucose, the body's main source of energy, is a type of sugar found in the blood. It is important to test blood glucose while fasting, because levels naturally rise after eating. Therefore, elevated blood glucose levels after a meal are not necessarily a sign of a medical problem. However, fasting blood glucose levels of 100 mg/dL or higher constitute hyperglycemia, which is a sign of diabetes.
Step 1
Record the time at which you finished your last meal or snack of the day.
Step 2
Go to sleep, and wake up at the time you normally do. Determine how long it has been since you finished eating your last meal the previous day. For example, if you recorded that you finished your last snack of the day at 10 P.M. and it is currently 5 A.M., it has been seven hours since you last ate.
Step 3
Delay blood glucose testing until at least eight hours have elapsed since you last ate. In this case, if you woke up seven hours after last eating, you must wait one additional hour before your test.
Step 4
Drink water while you wait for enough time to elapse to test your blood glucose. Drinking water keeps you hydrated, which is essential for overall health but also makes testing easier. Your blood thickens when dehydrated, making the process more difficult.
Step 5
Test your blood glucose in the manner prescribed by your physician after fasting for eight hours. Blood glucose testing can be performed at home with a glucometer or at a lab.
References
- "Foundations of Nursing"; Lois White, Gena Duncan and Wendy Baumle; 2010
- "Mosby's Manual of Diagnostic and Laboratory Tests"; Kathleen Deska Pagana PhD RN and Timothy J. Pagana MD FACS; 2009
- "Mayo Clinic Essential Diabetes Book"; Mayo Clinic; 2009
