AT III

Normal value ranges may vary slightly among different laboratories. Talk to your doctor about the meaning of your specific test results.

Lower-than-normal AT III may mean you have an increased risk of clotting. Abnormal results may not show up until you are an adult.

Examples of disorders and conditions associated with increased blood clotting include:

• Deep venous thrombosis
• Phlebitis (vein inflammation)
• Pulmonary embolus (blood clot traveling to lung)
• Thrombophlebitis (vein inflammation with clot formation)

Lower than normal AT III may be due to:

• Bone marrow transplant
• DIC (disseminated intravascular coagulation)
• AT III deficiency, an inherited condition causing lower blood clotting protein levels
• Liver cirrhosis
• Nephrotic syndrome

Higher than normal AT III may be due to:

• Use of anabolic steroids

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Antithrombin III Overview

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Antithrombin III Risks

Review Date: 06/02/2010
Reviewed By: David C. Dugdale, III, MD, Professor of Medicine, Division of General Medicine, Department of Medicine, University of Washington School of Medicine; Yi-Bin Chen, MD, Leukemia/Bone Marrow Transplant Program, Massachusetts General Hospital. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.

A.D.A.M., Inc. is accredited by URAC, also known as the American Accreditation HealthCare Commission (www.urac.org)