Coagulation Factor Tests
Reviewed
Also called: blood clotting factors, factor assays, factor assay by number (Factor I, Factor II, Factor VIII, etc.), by name (fibrinogen, prothrombin, hemophilia A, hemophilia B, etc.), coagulation panel
A coagulation factor test is used to find out if you have a problem with any of your clotting factors that may cause too little or too much blood clotting.
Specimen: blood
Why this test may be ordered
- An abnormal result on a blood test that checks how long it takes your blood to clot (PT/INR and/or PTT)
- A family health history of problems with clotting factors
- A health condition that may affect clotting factors (e.g., severe liver disease, lack of vitamin K, blood transfusions, cancer, immune disorders, autoimmune diseases, obesity, certain infections, prolonged immobility, lack of vitamins B6, B12, and folate)
- Symptoms of a bleeding disorder (heavy bleeding, frequent nosebleeds, blood in urine or stool, frequent large bruises, bleeding into muscles or joints, heavy menstrual periods)
- Symptoms of too much blood clotting (swelling, redness, warmth, pain in arms or legs, trouble breathing, nausea)
Preparation and collection
You don't need any special preparations for a coagulation factor test.
A health care professional will take a blood sample from a vein in your arm, using a small needle. After the needle is inserted, a small amount of blood will be collected into a test tube or vial. You may feel a little sting when the needle goes in or out. This usually takes less than five minutes.
There is very little risk to having a blood test. You may have slight pain or bruising at the spot where the needle was put in, but most symptoms go away quickly.
Understanding results
Your provider may need to order other tests to find the cause of a problem with your clotting factors.
- Lower than normal or missing clotting factor: Lower than normal levels of one or more clotting factors or a missing clotting factor may mean you have a bleeding disorder. Limitation: Depending on which clotting factors were tested, your results may show the type of bleeding disorder you have and how serious it is. Next step: There is no cure for inherited bleeding disorders, but treatment can help manage your condition. Treatment depends on the cause of your bleeding disorder.
- Higher than normal clotting factor levels: Higher than normal levels of one or more clotting factors may mean you have a disorder that makes your blood clot more than it should. Limitation: Your provider may need to order other tests to find the cause of a problem with your clotting factors. Next step: Your provider may recommend medicine and heart-healthy lifestyle changes to help prevent clots. You may also need to avoid hormone therapy for menopause and birth control pills with estrogen, because they may increase the risk of blood clots.
- Your provider may need to order other tests to find the cause of a problem with your clotting factors.
- Results should be interpreted by a healthcare professional.
What to do next
Talk with your provider to find out what your tests results mean and what treatment is best for you.
- What do my coagulation factor test results mean?
- Do I need any other tests?
- What treatment options are available for my condition?
Evidence source
Source: U.S. National Library of Medicine (MedlinePlus). Practices and reference ranges may differ in your country.