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    Blood Glucose

    Blood Glucose



    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 Reference fasting blood test Opens New Window or less than 2 hours before a 2-hour postprandial 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 (Dyrenium, Dyazide), hydrochlorothiazide (Esidrix, Oretic), niacin, propranolol (Inderal), or corticosteroids (prednisone). Some medicines can cause changes in your test results. Make sure that your doctor knows about any medicines you take and how often you take them.


    This information does not replace the advice of a doctor. Healthwise, Incorporated disclaims any warranty or liability for your use of this information. Your use of this information means that you agree to the Reference Terms of Use. Reference How this information was developed to help you make better health decisions.