Health Encyclopedia - Test
How the Test is Performed
How to Prepare for the Test
How the Test will Feel
Why the Test is Performed
Normal values are 60 - 150% inhibition.
Note: Normal value ranges may vary slightly among different laboratories. Talk to your doctor about the meaning of your specific test results.
The examples above show the common measurements for results for these tests. Some laboratories use different measurements or may test different specimens.
What Abnormal Results Mean
A lack (deficiency) of protein C can lead to excess clotting. These clots tend to form in veins, not arteries.
Protein C deficiency can be passed down through families (inherited) or it can develop with other conditions, such as:
- Chemotherapy use
- Disseminated intravascular coagulation (DIC)
- Liver disease
- Long-term antibiotic use
- Warfarin (Coumadin) use
Protein C levels rise with age, but this does not cause any health problems.
- Excessive bleeding
- Fainting or feeling light-headed
- Hematoma (blood accumulating under the skin)
- Infection (a slight risk any time the skin is broken)
Anderson J, Weitz JI. Hypercoagulable states. In: Hoffman R, Benz EJ Jr, Silberstein LE, Heslop HE, Weitz JI, eds. Hematology: Basic Principles and Practice. 6th ed. Philadelphia, PA: Saunders Elsevier; 2012:chap 142.
Schafer A. Thrombotic disorders: Hypercoagulable states. In: Goldman L, Schafer AI, eds. Goldman's Cecil Medicine. 24th ed. Philadelphia, PA: Saunders Elsevier; 2011:chap 179.
Reviewed By: Yi-Bin Chen, MD, Leukemia/Bone Marrow Transplant Program, Massachusetts General Hospital. Also reviewed by A.D.A.M. Health Solutions, Ebix, Inc., Editorial Team: David Zieve, MD, MHA, Bethanne Black, Stephanie Slon, and Nissi Wang.