Fibrin degradation products (FDPs) are the substances left behind when clots dissolve in the blood. This article discusses the blood test to measure these products.

The health care provider uses a needle to take blood from one of your veins. The blood collects into an airtight container. You may be given a bandage to stop any bleeding.

The laboratory specialist will run tests on the blood sample to measure the products that are left behind when blood clots dissolve.

Your health care provider may tell you to stop taking certain drugs before the test. Drugs that may increase FDPs include barbiturates, heparin, streptokinase, and urokinase.

Do not stop taking any medicine without first talking to your doctor.

When the needle is inserted to draw blood, some people feel moderate pain, while others feel only a prick or stinging sensation. Afterward, there may be some throbbing.

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

The result is normally less than 10 mcg/mL.

Note: mcg/mL = micrograms per milliliter

Increased FDPs may indicate primary or secondary fibrinolysis (clot-dissolving activity) from such conditions as:

• Abruptio placentae
• Burns
• Congenital heart disease
• Disseminated intravascular coagulation (DIC)
• Following cardiopulmonary (heart and lungs) pump surgery
• Following massive blood transfusion
• Hypoxia
• Infections
• Intrauterine fetal death
• Leukemia
• Liver disease (see cirrhosis)
• Portacaval shunt
• Preeclampsia
• Renal disease (see kidney failure)
• Septicemia
• Thromboembolic states
• Transplant rejection
• Transfusion reaction

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

Veins and arteries vary in size from one patient 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.