Oral glucose tolerance test
What the risks are
Veins and arteries vary in size from one patient to another and from one side of the body to the other. Obtaining a blood sample from some people may be more difficult than from others.
Other risks associated with having blood drawn are slight but may include:
- Excessive bleeding
- Fainting or feeling light-headed
- Hematoma (blood accumulating under the skin)
- Infection (a slight risk any time the skin is broken)
Factors that may affect the test results:
- Acute stress (for example, from surgery or an infection)
- Vigorous exercise
Several drugs may cause glucose intolerance, including:
- Beta-blockers (for example, propranolol)
- Certain psychiatric medications
- Corticosteroids (for example, prednisone)
- Oral contraceptives (birth control pills)
- Thiazide diuretics (for example, hydrochlorothiazide)
Before having the test, let your health care provider know if you are taking any of these medications.
Review Date: 05/23/2010
Reviewed By: David C. Dugdale, III, MD, Professor of Medicine, Division of General Medicine, Department of Medicine, University of Washington School of Medicine. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.