D-dimer test

Definition

D-dimer tests are used to check for blood clotting problems. Blood clots can cause health problems, such as:

• Deep vein thrombosis (DVT)
• Pulmonary embolism (PE)
• Stroke
• Disseminated intravascular coagulation (DIC)

Alternative Names

Fragment D-dimer; Fibrin degradation fragment; DVT - D-dimer; PE - D-dimer; Deep vein thrombosis - D-dimer; Pulmonary embolism - D-dimer; Blood clot to the lungs - D-dimer

How the Test is Performed

The D-dimer test is a blood test. You will need to get a blood sample drawn.

How to Prepare for the Test

No special preparation is necessary.

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 sensation. Afterward, there may be some throbbing or a slight bruise.

Why the Test is Performed

Your health care provider may order a D-dimer test if you are showing symptoms of blood clots, such as:

• Swelling, pain, warmth, and changes in skin color of your leg
• Sharp chest pain, trouble breathing, coughing up blood, and fast heart beat
• Bleeding gums, nausea and vomiting, seizures, severe stomach and muscle pain, and decreased urine

Your provider may also use the D-dimer test to see if treatment for DIC is working.

Normal Results

A normal test is negative. This means that you probably do not have problems with blood clotting.

If you are getting the D-dimer test to see if treatment is working for DIC, a normal or decreasing level of D-dimer means the treatment is working.

What Abnormal Results Mean

A positive test means that you may be making blood clots. The test does not tell where the clots are or why you are making clots. Your provider may order other tests to see where clots are located.

A positive test may be caused by other factors, and you may not have any clots. D-dimer levels can be positive due to:

• Pregnancy
• Liver disease
• Recent surgery or trauma
• High lipid or triglyceride levels
• Heart disease
• Being over 80 years old

This makes the test mostly useful when it is negative, when many of the above causes can be ruled out.

Risks

Veins 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.

Risks associated with having blood drawn are slight, but may include:

• Bleeding from where the needle was inserted
• Fainting or feeling lightheaded
• Hematoma (blood collecting under the skin)
• Infection (a slight risk any time the skin is broken)

References

Goldhaber SZ. Pulmonary embolism. In: Zipes DP, Libby P, Bonow RO, Mann DL, Tomaselli GF, Braunwald E, eds. Braunwald's Heart Disease: A Textbook of Cardiovascular Medicine. 11th ed. Philadelphia, PA: Elsevier Saunders; 2019:chap 84.

Kline JA. Pulmonary embolism and deep vein thrombosis. In: Walls RM, Hockberger RS, Gausche-Hill M, eds. Rosen's Emergency Medicine: Concepts and Clinical Practice. 9th ed. Philadelphia, PA: Elsevier; 2018:chap 78.

Siegal D, Lim W. Venous thromboembolism. In: Hoffman R, Benz EJ, Silberstein LE, et al, eds. Hematology: Basic Principles and Practice. 7th ed. Philadelphia, PA: Elsevier; 2018:chap 142.