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    Blood-Clotting Disorders

    Blood-Clotting Disorders

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    Topic Overview

    Some people are born with an increased tendency to form blood clots. These are called inherited blood-clotting disorders. They are often related to:

    • Mutated genes (such as factor V Leiden, factor II).
    • Decreased amounts of certain proteins. These may include protein C, protein S, and antithrombin III.
    • Increased levels of other substances. These may include antiphospholipid antibodies and lupus anticoagulant.

    Other people get blood clots because of a health problem. Blood clots can happen after surgery or injury. And they can happen when a person doesn't move around for a long time.

    Blood clots can be especially serious when they are in the legs ( deep vein thrombosis ) and in the lungs ( pulmonary embolism ).


    There are several tests that can help find the cause of a blood clotting problem. Talk to your doctor about whether you need testing.

    These tests may include:

    • Fibrinogen.
    • Antithrombin.
    • Protein C.
    • Protein S.
    • Factor V Leiden.
    • Antiphospholipid antibody
    • Lupus anticoagulant.

    Related Information


    Other Works Consulted

    • Lipe B, Ornstein DL (2011). Deficiencies of natural anticoagulants, protein C, protein S, and antithrombin. Circulation, 124(14): e365-e368.


    ByHealthwise Staff
    Primary Medical Reviewer E. Gregory Thompson, MD - Internal Medicine
    Adam Husney, MD - Family Medicine
    Specialist Medical Reviewer Jeffrey S. Ginsberg, MD - Hematology

    Current as ofJune 4, 2016

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