After blood is drawn, pressure is applied (with cotton or gauze) to the puncture site. You may be given a snack or some orange juice after the oral glucose tolerance test. ou may resume your normal diet, activities, and any medications withheld before the test.

Blood may collect and clot under the skin (hematoma) at the puncture site; this is harmless and will resolve on its own. For a large hematoma that causes swelling and discomfort, apply ice initially; after 24 hours, use warm, moist compresses.

Risks and Complications of Glucose Tests

  • The fasting, postprandial, and HbA1c tests are associated with no risks.
  • You may experience symptoms of hypoglycemia (weakness, restlessness, hunger, sweating, nervousness) during the oral glucose tolerance test. Tell your doctor immediately if this happens. If these symptoms persist, you will be given orange juice, and the test will be discontinued.
  • Slight risks associated with having blood drawn include excessive bleeding, fainting or feeling light-headed, hematoma (blood accumulating under the skin causing a bruise or lump) and infection.

Results of Glucose Tests

  • Chemical tests are performed on the blood and urine samples to measure the level of glucose. These results and the presence of risk factors for diabetes will help your doctor in making a diagnosis.
  • If you test positive for diabetes, the condition can be treated with dietary measures, exercise, and, if necessary, oral glucose-lowering medications or insulin injections.


The Johns Hopkins Consumer Guide to Medical Tests

Simeon Margolis, M.D., Ph.D., Medical Editor

Updated by Remedy Health Media

Publication Review By: the Editorial Staff at

Published: 13 Jan 2012

Last Modified: 31 Jul 2014