Normal Values:

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

What abnormal results mean:

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)

Lower-than-normal AT III may be due to:

• Bone marrow transplant
• DIC (disseminated intravascular coagulation)
• Other coagulation disorders
• An inherited condition causing lower blood clotting protein levels
• Liver disorders
• Nephrotic syndrome

Higher-than-normal AT III may be due to:

• Use of anabolic steroids