A D-dimer test is a lab test that helps diagnose blood clotting conditions. The test measures the levels of a protein fragment that remains in your blood after multiple blood clots break down.
A high level of D-dimer in your blood doesn’t always mean you have a blood clotting condition, and it isn’t enough on its own to make a diagnosis. However, it can point you and your doctor toward the best next step. This might be additional blood tests, imaging tests, or both.
If you have a blood clotting condition, doctors can use a D-dimer test to check your progress and see how well you respond to treatment.
D-dimer is a protein fragment your body makes when a blood clot dissolves.
Usually, the level of D-dimer in the blood is low. However, when your body forms and breaks down multiple blood clots, doctors will evaluate D-dimer levels in the blood.
A D-dimer test is a blood test that measures the amount of D-dimer in the blood. It can indicate that you need additional testing, such as further lab tests or imaging tests, to see what causes high levels.
Your doctor might order a D-dimer test if they suspect you have a blood clotting condition.
Conditions a D-dimer test can help diagnose include:
- Deep vein thrombosis (DVT): DVT is a type of blood clot that develops in a vein and partially or fully blocks the flow of blood. DVTs often occur in the pelvis and legs, but they can occur throughout the body.
- Pulmonary embolism (PE): A PE is a type of blood clot that occurs when a blood clot from one part of your body travels through your bloodstream and lodges in the blood vessels of your lungs. PEs often begin in the arms or legs.
- Stroke: A stroke occurs when a blood vessel in your brain experiences a blockage or bursts.
- Disseminated intravascular coagulation (DIC): DIC is a rare condition that causes multiple blood clots to form throughout the body. It can lead to serious organ damage.
Doctors can also use a D-dimer test to see how well you respond to treatment for a blood clotting condition. This is primarily for people with DIC. Periodic D-dimer testing can help make sure treatments reduce the number of clots in your body.
A D-dimer test is a blood test. A phlebotomist or medical assistant usually performs it.
The healthcare professional will collect a small sample of blood in a test tube. Medical professionals will test the blood in a lab to determine D-dimer levels.
A D-dimer test is a standard blood test. You can often have this test on the day your doctor orders it. You don’t need to do anything to prepare for the test.
A D-dimer test is usually safe. Blood tests do not typically have serious risks or side effects.
It’s common to experience minor discomforts, such as a bruise, slight bleeding, or soreness at the site of the blood draw, but this typically resolves without issue.
Your results will indicate the level of D-dimer in your blood.
There are several methods of measuring D-dimer, and standard ranges differ among facilities.
In general, test results within or below the testing facility’s standard range can mean you do not have a clotting condition. Test results above the testing facility’s standard range may be a sign of a clotting condition.
The results of a D-dimer test aren’t enough to diagnose any clotting condition.
Results that are higher than the testing facility’s standard range don’t always mean you have a clotting condition. They also don’t point to a specific clotting condition. However, they can tell a doctor that additional testing is the best next step.
You can learn more about D-dimer tests by checking out the answers to some commonly asked questions.
What causes a D-dimer test result to be high?
A clotting disorder can cause a D-dimer test result to be high. However, it’s not the only possibility of high results. High results can also result from:
D-dimer levels are sometimes also higher in older adults. That’s one of many reasons why additional testing is so important. High D-dimer test results do not always mean you have a clotting condition.
What is a D-dimer normal range?
Different labs use different measurements for D-dimer testing. There is no one set standard range. When you get your test results back, they will include the specific lab’s standard value, and you can compare your results against that value.
Can a D-dimer test be used for COVID-19?
A D-dimer test can help diagnose blood clotting conditions. Doctors perform the test through a simple blood draw, and it’s a great first step in the diagnostic process.
Higher than standard results can indicate a blood clotting condition. However, there are other causes of high D-dimer levels. A D-dimer test isn’t enough on its own to diagnose any condition, but the information it provides is valuable to doctors.