What is a D-Dimer Test?
A D-Dimer Test is a form of a blood test which is done to identify any blood clots that may be forming in the vascular system of the body of an individual. A D-Dimer Test is extremely useful in diagnosing deep venous thrombosis or pulmonary embolus, both clotting disorders, in an individual. However, certain other conditions in which blood clots have a role to play can also be diagnosed by doing a D-Dimer Test.
It should be noted that this D-Dimer Test may always not be conclusive and at times may lead to a misdiagnosis. Thus it is imperative for physicians to ensure that utmost care is taken when analyzing the results of this test and the precise timing of conducting a D-Dimer.
Coming to the anatomy, formation of blood clot is a natural process that is followed by the body to prevent excessive flow of blood after an injury or as a result of any damage to a blood vessel in the body. The purpose of the clot is to fill in the leak and stop blood flow. However, when a blood clot is formed, it is imperative that it does not grow in size to such an extent that it completely blocks the blood vessel.
This is done by another process that takes place during blood clotting. This process releases a protein called Plasmin which limits the size of the clot by constantly degrading it. In a healthy individual, there is perfect sync between the two processes; however, if there is any underlying medical condition, there is an increase in the size of the clot ultimately resulting in conditions like pulmonary embolus or DVT.
What is the Purpose of a D-Dimer Test?
The primary purpose of a D-Dimer test is to identify whether any unusual blood clotting is occurring somewhere in the body. This information is extremely useful when diagnosing a condition like DVT or PE where the levels of D-Dimer will be abnormal.
What Does an Elevated D-Dimer Test Mean and What Causes it to Become Elevated?
A D-Dimer test is either negative or positive. A negative test indicates that there is no presence of any unusual clotting activity occurring anywhere in the body. On the other hand a positive D-Dimer test indicates the presence of an underlying medical condition which is affecting the normal clotting process of the body.
A D-Dimer test is said to be positive when its levels are elevated. This indicates towards excessive blood clot formation and degradation happening simultaneously somewhere in the body even though this test does not pinpoint the location of the abnormality. Venous thromboembolism and disseminated intravascular coagulation are the two primary conditions that cause an elevated D-Dimer, especially the latter in which the levels are abnormally high.
However, there are also certain other causes that may result in an elevated D-Dimer. Individuals having had a recent surgical procedure tend to have elevated levels. Also individuals having had a trauma, infection, myocardial infarction, or some metastatic disease also tend to have elevated D-Dimer. Liver disease is yet another serious condition in which D-Dimer levels are elevated. Some of the medical conditions that are associated with elevated D-Dimer are:
- Old age
- Nicotine abuse
- African American decent
- Recent surgical procedure
- Atrial fibrillation
- Acute coronary artery disease
- Liver Dysfunction
What are the Symptoms of Elevated D-Dimer?
Since the primary culprits behind elevated D-Dimer levels are Pulmonary Embolus, DVT or disseminated intravascular coagulation thus elevation can be suspected in cases of the patient complains of the following
- Pain in the leg, either left or right, along with severe tenderness to palpation
- Swelling in the leg
- Skin coloration in the affected leg
These symptoms are similar to that of a DVT. In case if PE is suspected then the patient may complain of
- Breathing difficulties with at times labored breathing
- Persistent cough with Hemoptysis
- Pain in the middle of the chest
If the patient has disseminated intravascular coagulation then he may complain of
- Bleeding gums
- Severe abdominal pain
- Severe bouts of vomiting
- Decreased urinary output
However, the best part about a D-Dimer test is that it is extremely useful in ruling out these above mentioned conditions as a cause of symptoms. This is because if the symptoms are not caused by PE, DVT, or DIC then obviously the levels of D-Dimer will not be elevated.
What is the Treatment of Elevated D-Dimer?
The treatment for elevated D-Dimer depends on the underlying cause. Once a cause is identified, treating it will automatically bring down the D-Dimer levels back to normal. For example if DVT is causing elevated D-Dimer then standard treatment for it includes use of blood thinners or clot busters which breaks the clot. Once the clot is removed then the D-Dimer levels come back to normal.
Similarly, if the elevated D-Dimer is caused due to pregnancy related issues then the levels should come back to normal after delivery of the baby. Management of conditions like liver dysfunction, atrial fibrillation, cancer helps in bringing down elevated D-Dimer.