What is the D-dimer test for blood clots?

The D-dimer test is a blood test used to help assess the likelihood of a blood clot, such as a deep vein thrombosis (DVT). D-dimer is a small protein fragment that's present in the blood after a blood clot dissolves. Elevated levels of D-dimer may suggest an active clotting process somewhere in the body. However, it's important to note that elevated D-dimer levels can occur in other conditions, such as inflammation, infection, or recent surgery, which can make interpretation complex.

In clinical practice, the D-dimer test is often used in conjunction with a clinical assessment and risk stratification models to evaluate the probability of DVT. A negative D-dimer test in a low-risk patient can effectively rule out the presence of a significant blood clot, reducing the need for further imaging. Conversely, a positive D-dimer test might prompt further investigation, such as an ultrasound, to confirm the presence of a clot. Anyone with concerns about blood clot symptoms or test results should discuss their specific situation with their healthcare provider.