What is a D – Dimer test?
The human body is designed to heal itself through multiple ways and methods. When a person suffers a serious injury that causes excessive bleeding, the body begins to form clusters of blood in the site in order to control the amount of blood loss. This process is known as Hemostasis—a completely natural part of the human healing process.
Once the wound heals and the clot is no longer required, the body disintegrates the blood clot by breaking it down. This causes some substances from the clot to remain in the body for a short while afterwards. One such substance is the D-Dimer, a fragmented protein that is left behind after the dissolution of a blood clot.
Normally, these remaining substances also dissolve after a while. However, in some cases, an individual may suffer from a condition that leads to the formation of blood clots in their body even when there is no injury. This causes the continuous or substantial formation and disintegration of D – dimer in the body which increases its level in blood.
A D-dimer test checks the d–dimer levels in the blood to examine the possibility of a blood clotting disorder in an individual. Excessive blood clotting in the body can be dangerous, and even life-threatening since it can lead to blockage in the lungs and arteries thus hampering blood flow to all parts of the body.
What does a D – dimer test do?
A D–Dimer test is used to examine the levels of d – dimer in blood to check for blood clotting disorders such as:
- Deep Vein Thrombosis (DVT) – DVT causes blood clots to form deep within a vein, usually in the leg. It can lead to swelling and leg pain but may also be asymptomatic.
- Pulmonary Embolism (PE) – This is when a blood clot formed in any part of the body flows through the blood and causes blockage in the blood vessels of the lungs. PE is often caused due to DVT. Symptoms of PE include difficulty in breathing, chest pain, and coughing.
- Disseminated Intravascular Coagulation (DIC) – This condition leads to the formation of multiple blood clots around various parts of the body. It can be caused by serious injuries/ infections or cancer and can be potentially life-threatening due to the risk of organ damage it poses. Symptoms of DIC include nausea, vomiting, bleeding gums, and abdominal pain.
Doctors perform the D dimer test to rule out the possibility of certain conditions or check if a specific disease is causing symptoms in an individual.
How is the test performed?
The test is usually performed in the emergency room and is similar to regular blood tests. A doctor or a nurse uses a needle to withdraw blood into a vial, which is later examined in the lab. Patients may feel a slight tinge when the needle is inserted and minimal soreness at the site of injection afterwards. The results are normally declared quickly.
What do the test results signify?
The D dimer blood test does not reveal the cause or location of a blood clot, but simply if it is present. The result is provided in the form of a positive or a negative result.
A negative result is declared when d – dimer levels are below the threshold and it signifies that there is no imminent risk of blood clots. A positive result on the other hand indicates the presence of abnormally high d – dimer levels in the blood, which leads to the possibility of a blood clot being present. However, a high d – dimer level is not inherently connected to the presence of blood clots. Various other factors such as recent surgery, infection, heart attack, liver disease, and cancer may also contribute towards increased d – dimer levels in the body.
The process of blood clotting is performed by the body by creating strings of protein known as fibrin that interlink to form a net-like structure. This net prevents excessive blood loss by keeping the blood clot in place at the site of the wound.
Once the site is healed, an enzyme called plasmin causes the clot to disintegrate and dissolve, and the bits and parts formed in this process of disintegration are called Fibrin Degradation Products (FDP).
The D – dimer is one of these fragments. Since d – dimers are created whenever fibrin is formed and dissolved by the body, a high level of d- dimer is indicated whenever this process occurs, such as during pregnancy. Therefore, a high d – dimer level can be caused by several factors besides blood clotting.
The D-dimer blood test does not provide specific results and therefore, if an individual is tested positive, they are required to undergo more tests as instructed by the doctor in order to streamline the cause.
If you are experiencing any physical anomalies such as leg swelling and pain, chest pain, shortness of breath, and skin discoloration, contact a doctor at the earliest and take necessary actions as prescribed.