Site Map

Factor V assay

Labile factor; Proaccelerin; Ac-globulin

The factor V (five) assay is a blood test to measure the activity of factor V. This is one of the proteins in the body that helps the blood clot.

I Would Like to Learn About:

How the Test is Performed

A blood sample is needed.

How to Prepare for the Test

No special preparation is needed.

How the Test will Feel

When the needle is inserted to draw blood, some people feel moderate pain. Others feel only a prick or stinging. Afterward, there may be some throbbing or slight bruising. This soon goes away.

Why the Test is Performed

This test is used to find the cause of too much bleeding (decreased blood clotting). This decreased clotting may be caused by an abnormally low level of factor V.

Normal Results

The value is normally 50% to 200% of the laboratory control or reference value.

Normal value ranges may vary slightly among different laboratories. Some labs use different measurements or may test different samples. Talk to your health care provider about the meaning of your specific test results.

What Abnormal Results Mean

Decreased factor V activity may be related to:

Risks

There is little risk involved with having your blood taken. Veins and arteries vary in size from one person 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:

This test is most often performed on people who have bleeding problems. The risk of excessive bleeding is slightly greater than for people without bleeding problems.

Related Information

Factor V deficiency
Liver disease
Cirrhosis
Fibrinolysis - primary or secondary

References

Chernecky CC, Berger BJ. Factor V (labile factor, proaccelerin, Ac-globulin) - blood. In: Chernecky CC, Berger BJ, eds. Laboratory Tests and Diagnostic Procedures. 6th ed. St Louis, MO: Elsevier Saunders; 2013:502-503.

Pai M. Laboratory evaluation of hemostatic and thrombotic disorders. In: Hoffman R, Benz EJ, Silberstein LE, et al, eds. Hematology: Basic Principles and Practice. 7th ed. Philadelphia, PA: Elsevier; 2018:chap 129.

BACK TO TOP

Review Date: 1/29/2019  

Reviewed By: Todd Gersten, MD, Hematology/Oncology, Florida Cancer Specialists & Research Institute, Wellington, FL. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.

ADAM Quality Logo

A.D.A.M., Inc. is accredited by URAC, for Health Content Provider (www.urac.org). URAC's accreditation program is an independent audit to verify that A.D.A.M. follows rigorous standards of quality and accountability. A.D.A.M. is among the first to achieve this important distinction for online health information and services. Learn more about A.D.A.M.'s editorial policy, editorial process and privacy policy. A.D.A.M. is also a founding member of Hi-Ethics. This site complies with the HONcode standard for trustworthy health information: verify here.

The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed medical professional should be consulted for diagnosis and treatment of any and all medical conditions. Links to other sites are provided for information only -- they do not constitute endorsements of those other sites. © 1997- 2019 A.D.A.M., a business unit of Ebix, Inc. Any duplication or distribution of the information contained herein is strictly prohibited.

A.D.A.M. content is best viewed in IE9 or above, Firefox and Google Chrome browser.