Coagulation Factor Tests

What is Coagulation Factor Test?

Coagulation factor tests—also known as clotting factor tests—are blood tests used to diagnose clotting conditions (coagulation disorders). The body needs clotting factors for blood to clot and heal a wound. To diagnose coagulation disorders, a doctor will look for signs of too much or too little clotting. Clotting factor tests measure the level of different clotting factors in the blood.

Preparation for the Test

No specific preparation is typically needed for a coagulation factor test. However, it is important for people to let their doctor know if they are taking any blood-thinning medications or if they have had any serious bleeding episodes in the past. This information helps the doctor determine the best course of action.

Procedure

To perform a coagulation factor test, a doctor will take a small sample of blood and send it to the laboratory for analysis. The analysis will measure the activity levels of various clotting factors. Generally, it takes several days to get the results back.

Types

• Prothrombin time test (PT)
• Partial thromboplastin time test (PTT)
• Activated partial thromboplastin time test (aPTT)
• Fibrinogen test
• D-dimer

Risks

There are no serious risks associated with coagulation factor tests. The only risk is bleeding at the site of the injection. To reduce this risk, the person should apply pressure to the site after the injection.

When to Get a Coagulation Factor Test

A coagulation factor test may be done for several reasons, including:

• to diagnose a bleeding disorder such as hemophilia or von Willebrand disease
• to assess a person’s response to clotting factor replacement therapy
• before and after major surgery to monitor for bleeding and clotting problems
• if there is a suspicion of a blood clotting disorder
• if a person has a family history of blood clotting disorders

Why Get a Coagulation Factor Test?

Coagulation factor tests give doctors important information about the level of clotting factors in the blood. This helps them diagnose and treat blood clotting disorders. Without this test, these disorders can be difficult to diagnose and treat without causing serious harm to the person.