Definition

Fibrin degradation products (FDPs) are the substances left behind when clots dissolve in the blood. A blood test can be done to measure these products.

Alternative Names

FDPs; FSPs; Fibrin split products; Fibrin breakdown products

How the Test is Performed

A blood sample is needed.

How to Prepare for the Test

Certain medicines can change blood test results.

• Tell your health care provider about all the medicines you take.
• Your provider will tell you if you need to temporarily stop taking any medicines before you have this test. This includes blood thinners such as aspirin, heparin, streptokinase, and urokinase, which make it hard for the blood to clot.
• Do not stop or change your medicines without talking to your provider first.

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 done to see if your clot-dissolving (fibrinolytic) system is working properly. Your provider may order this test if you have signs of disseminated intravascular coagulation (DIC) or another clot-dissolving disorder.

Normal Results

The result is normally less than 10 mcg/mL (10 mg/L).

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

What Abnormal Results Mean

Increased FDPs may be a sign of primary or secondary fibrinolysis (clot-dissolving activity) due to a variety of causes, including:

• Blood clotting problems
• Burns
• Problem with the heart's structure and function that is present at birth (congenital heart disease)
• Disseminated intravascular coagulation (DIC)
• Low level of oxygen in the blood
• Infections
• Leukemia
• Liver disease
• Problem during pregnancy such as preeclampsia, placenta abruption, miscarriage
• Recent blood transfusion
• Recent surgery that involved a heart and lung bypass pump, or surgery to lower high blood pressure in the liver
• Kidney disease
• Transplanted organ rejection
• Large blood clots inside the body

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 with having blood drawn are slight, but may include:

• Excessive bleeding
• Fainting or feeling lightheaded
• Multiple punctures to locate veins
• Hematoma (blood accumulating under the skin)
• Infection (a slight risk any time the skin is broken)

References

Levi M. Disseminated intravascular coagulation. In: Hoffman R, Benz EJ, Silberstein LE, et al, eds. Hematology: Basic Principles and Practice. 8th ed. Philadelphia, PA: Elsevier; 2023:chap 137.

Schafer AI. Approach to the patient with bleeding and thrombosis. In: Goldman L, Schafer AI, eds. Goldman-Cecil Medicine. 26th ed. Philadelphia, PA: Elsevier; 2020:chap 162.