What Is a D-Dimer Test?

A D-dimer test is a blood test used to help diagnose a clotting disorder or other health condition. It measures the amounts of a specific substance in your blood that is a result of blood clots dissolving in the body. A D-dimer test is frequently ordered by medical professionals to decide whether to conduct additional diagnostic tests for conditions like deep vein thrombosis (DVT) or an ongoing blood clotting problem.

D-dimer tests are part of a clinical assessment for an existing venous clotting disorder or perceived risk of having one. Sometimes, individuals may need to be tested for DVT or pulmonary embolism due to their symptoms and their medical history. In other cases, a healthcare professional will suggest the test if they are concerned that a patient may be at risk of developing a clotting disorder due to certain factors, such as age, a recent surgery or pregnancy.

How the Test Works

D-dimer tests measure the levels of a protein fragment in the bloodstream called a fibrin degradation product (FDP). FDPs are created when plasmin, an enzyme responsible for breaking down fibrin (the protein material of clots), breaks down the clot. The FDPs are produced as byproducts of this breakdown process, and their presence in the blood indicates that the body is actively dissolving clots.

The D-dimer test is a simple blood test taken from the arm that does not involve any specific preparation. A healthcare professional will draw the blood in an anticoagulant tube, which will allow the blood to clot sufficiently.

When to Consider Having a D-dimer Test

Medical professionals may suggest a D-dimer test for individuals with symptoms such as persistent leg pain and swelling, difficulty breathing, chest pain, coughing up blood, and pale or blue-colored skin and lips. These symptoms could indicate the presence of a clot in the lungs (pulmonary embolism) or in the legs (deep vein thrombosis), so a diagnostic assessment may need to be done to confirm the underlying cause.

The results of a D-dimer test are usually available relatively quickly. If the levels of FDPs in the blood are higher than normal, it usually means that a clot has formed and is interfering with the flow of blood. A positive result enables the medical professional to focus their assessment on the occurrence of a clot and other factors such as an underlying health condition.

Conclusion

The D-dimer test is an essential part of a diagnostic assessment for a venous clotting disorder. It helps medical professionals to determine if a clot has formed and is interfering with the flow of blood in the legs or lungs. A D-dimer test is a simple blood test that can provide results relatively quickly, enabling healthcare professionals to decide on the best course of action.