Blood Glucose

2-hour Postprandial Blood Sugar Test, Fasting Blood Sugar Test, Random Blood Sugar Test

What Affects the Test

Reasons you may not be able to have the test or why the results may not be helpful include:

• Eating or drinking less than 8 hours before a fasting blood test or less than 2 hours before a 2-hour post-prandial test.
• Drinking alcohol.
• Illness or emotional stress, smoking, and caffeine.

Taking a medicine, such as birth control pills, medicines used to treat high blood pressure, phenytoin (Dilantin), furosemide (Lasix), triamterene, hydrochlorothiazide, niacin, propranolol (Inderal), or corticosteroids (prednisone), can cause changes in your test results. Make sure that your doctor knows about any medicines you take and how often you take them.

Go to previous section	Go to top of page	Go to next section
Author:	Caroline Rea, RN, BS, MS	Last Updated: September 14, 2007
Medical Review:	Caroline S. Rhoads, MD - Internal Medicine Alan C. Dalkin, MD - Endocrinology Andrew Swan, MD, CCFP, FCFP - Family Medicine
© 1995-2008 Healthwise, Incorporated. Healthwise, Healthwise for every health decision, and the Healthwise logo are trademarks of Healthwise, Incorporated.This information does not replace the advice of a doctor. Healthwise disclaims any warranty or liability for your use of this information. Your use of this information means that you agree to the Terms of Use. How this information was developed to help you make better health decisions.