D-dimer
D-dimer is a protein fragment formed during the clotting and breakdown process of blood, measurable through a blood test. When clotting is active in the body, fibrin is produced and subsequently broken down by the body. D-dimer emerges during this process. Heart diseases, especially the formation of blood clots due to narrowing of the coronary arteries leading to coronary artery disease, can lead to this process becoming active, resulting in the production and elevation of D-dimer.
What is the D-dimer Test?
The D-dimer test is a blood test used to determine whether there is a clotting (thrombosis) problem in the blood. This test measures the amount of D-dimer, a protein produced in the body to break down blood clots. D-dimer may not be detectable or may only be seen at very low levels in the body unless it is actively producing and breaking down significant blood clots. A positive or elevated D-dimer indicates a clotting condition. However, the D-dimer test does not determine the specific clotting condition or the location of the clot in the body.
When is the D-dimer Test Ordered?
The D-dimer test is generally used to evaluate blood clotting and clotting disorders. It measures the levels of D-dimer in circulation when blood clots form or dissolve in the body. An increase in D-dimer levels may indicate the breakdown of existing blood clots in the body. This test is usually ordered in the following conditions:
1. Deep Vein Thrombosis (DVT):
Clots formed in the deep veins of the legs.
2. Pulmonary Embolism:
A clot blocking an artery in the lungs.
3. Coagulation Disorders:
Abnormalities in blood clotting or clot dissolution processes.
4. Disseminated Intravascular Coagulation (DIC):
Excessive clot formation leading to bleeding.
5. Conditions at risk of heart attack or stroke:
In some cases, to evaluate the risk of these conditions.
6. During Pregnancy:
Sometimes ordered to assess the risk of thrombosis during pregnancy.
7. Inflammatory diseases and conditions like cancer:
These conditions can sometimes increase the risk of clot formation.
Why is the D-dimer Test Conducted?
A specialist doctor may request a D-dimer test based on certain symptoms. These conditions include:
Deep vein thrombosis (DVT)
Pulmonary embolism (Lung clot)
Disseminated intravascular coagulation (DIC)
Stroke
What is D-dimer Elevation (Quantitative D-dimer)?
Elevated D-dimer levels may indicate a clotting problem or the presence of such a risk. However, quantitative elevation in D-dimer does not always imply blood clotting, and further tests may be required to confirm the presence of clotting. It's important to consult a specialist doctor for evaluation and disease detection in case of D-dimer elevation as it could be indicative of potential heart disease.
What Causes D-dimer Elevation?
While blood clotting is the primary cause of elevated D-dimer levels, various other factors can lead to an increase in D-dimer. Some other conditions that might cause D-dimer elevation include:
Pregnancy
Smoking
Cancer
Sepsis
Heart disease
Post-surgery
Trauma
Infection
Old age
What is D-dimer Decrease?
A decrease in D-dimer indicates that the value in the body is within normal ranges. D-dimer decrease implies the absence of clotting and a lack of clotting risk. If diagnosed with disseminated intravascular coagulation (DIC) and undergoing treatment, having normal or low levels of D-dimer in the blood likely indicates that the treatment is progressing well.