D-dimer Blood Test Results Explained


The D-dimer blood test is ordered to determine if there is the presence of an inappropriate blood clot somewhere in the body. The two most common reasons for this test to be ordered is because a pulmonary embolism is suspected or there are signs and symptoms of a deep vein thrombosis. It can also be used to determine if there is a need for further testing to eliminate the possibility of diseases or genetic disorders that may cause the blood to clot in abnormal ways.

When To See a Doctor

Most people will have this blood test ordered for them in the emergency room of their local medical facilities. That is because the symptoms of deep vein thrombosis can be worrisome and need to be treated immediately. This includes a tenderness and pain that is only felt in one leg. There may also be swelling in the leg and as the blood pools behind the clot, there can be discoloration that is similar to a bruise as well.

The same is true for the signs and symptoms of a pulmonary embolism. This happens when a blood clot makes its way to the lung and stays there. This may cause a sudden shortness of breath, cause painful and labored breathing, and may cause the individual to cough up blood regularly. A rapid pulse and chest pain associated with the lungs may be the only symptoms experienced, however, so any unusual changes should be noted.

The D-dimer blood test is useful because it is non-invasive and quickly rules out excessive clotting. It may not be ordered, however, if the symptoms presented indicate a pulmonary embolism as time of treatment is of the essence.

What Do My Test Results Mean?

Test results will either be positive or normal, which some medical providers which may communicate as being “negative.” When there is a normal result, then there is a good chance that the symptoms being experienced are not associated with an acute clot. A negative test is useful to eliminate risks in low to moderate risk individuals who have have experienced a thrombosis.

A positive D-dimer blood test result indicates that there may be a significant blood clot present somewhere or that the clot recently began to degrade and break down. It will not, however, let medical providers know where the clot has formed. It simply informs the medical provider that a blood clot has indeed formed and could put a patient’s life at risk if left untreated.

Some people may also experience a positive D-dimer blood test because of certain health events. Some cancers are known to cause a positive result, as is a heart attack. Certain infections or a trauma have also been known to cause positive results. When liver disease causes the fibrin to not be cleared properly, a positive test result may also be present. Women who are pregnant will commonly test positive, but should have results return back to normal after childbirth.

Here’s What You Need to Know

The specificity of the D-dimer blood test is rather low. It can indicate the presence of a potential blood clot, but it cannot lead to a diagnosis of where that clot may be. People who have been diagnosed with rheumatoid arthritis may test positive even without the presence of a blood clot, which can be problematic if both conditions co-exist.

Children are not typically given the D-dimer blood test. The results seen from this testing is not considered to be reliable at this time.

If there is a suspected risk of a blood clot and the blood test results explained here are positive, then an ultrasound may be requested to help determine if there is a specific clot that must be treated. Should a clot be found, certain medications that thin the blood and prevent coagulation, such as warfarin, may be prescribed to alleviate the condition and prevent abnormal clotting in the future.

If someone has a history of inappropriate blood clotting, the test may be proactively given during annual exams just to eliminate the risk of a clot developing without any signs or symptoms.

The D-dimer blood test may not be considered useful for all situations, but it can provide the first steps toward a diagnosis in certain individuals. Only a medical provider can interpret what your results mean, so be sure to discuss all of these circumstances at your next appointment so that a clear treatment plan can be developed with your feedback included.