D-DIMER Test

Our body creates substances to help heal and stay healthy. Among these is a protein called D-dimer, which is a small protein made when blood clots dissolve in the body. A D-dimer test checks for D-dimer levels in the blood.

Blood clotting is an essential process in the body. It prevents excessive blood loss during injury. Without blood clotting, you stand the chance of losing too much blood, which can prove fatal. In the normal course, blood clots dissolve as the injury heals. Sometimes, blood clots may not dissolve after the injury heals. In other cases, they may sometimes form without a real injury. These are typical signs of a blood clotting disorder that can prove quite dangerous.

Clotting episodes are usually referred to as thrombotic episodes. A D-dimer test is conducted to eliminate the possibility of thrombotic episodes and to help diagnose other conditions related to thrombosis. For individuals at risk of thrombosis, a D-dimer blood test can determine the likely presence of a clot. The D-dimer report will let you know whether further investigations are required.

Detection of blood clots is essential since they can obstruct blood flow in the body. In the legs, they can cut off supply and cause pain, swelling and tissue damage. A clot in the lungs called a pulmonary embolism, may prevent breathing and prove fatal. The major cause of heart attacks is clots in the arteries. When an artery in the brain is blocked, it leads to a stroke. In such cases, the D-dimer test can prove exceptionally useful.

In addition, the D-dimer test is very valuable in diagnosing a condition called DIC or disseminated intravascular coagulation. The body forms numerous small blood clots that leave the individual prone to excessive bleeding.

In addition, the D-dimer blood test also helps understand the risk and progression in cases of pneumonia and COVID-19.

Cases of venous thromboembolism or thrombosis in the veins are as prevalent in India as anywhere else in the world. Awareness of the condition is significantly lower in the country. With an incidence of about 17 for every 10,000 admissions, the cases have been noted to be on the rise, owing mainly due to greater awareness among the physician community. This increased awareness could help reduce the severity of the cases as well as the number of related deaths.

Other Names of D-Dimer Test

You may notice your physician or a hospital refer to the D-dimer test using the below terms:

• Fibrin degradation fragment
• Fragment D-dimer

Who needs the D-dimer test and why?

Although the D-dimer blood test is only an indicator of a clot and does not tell you exactly where it is located, it can help avoid fatalities. The D-dimer test is an important marker that can help rule out serious conditions like:

• Pulmonary embolism or clot in the lungs
• Deep vein thrombosis
• Stroke
• Heart attack

Your doctor may suggest a D-dimer procedure in suspected cases of deep vein thrombosis if the following symptoms are noticed:

• Swelling or discolouration in the leg
• Pain or tenderness in the leg, most commonly in only one limb

In the case of pulmonary embolisms, the suspected symptoms that require a D-dimer test report include:

• Laboured breathing or shortness of breath
• Elevated heart rate
• Lung-related pain (pain in chest and back)
• Severe coughing
• Blood in the sputum

Apart from these symptoms, there is an increased risk of thrombosis in the listed cases. A D-dimer test is used in the diagnosis of possible clots in the following ailments:

• Acute gastrointestinal haemorrhage
• Acute coronary syndromes
• Thrombosis in the arteries or veins
• Aortic dissection
• Infections
• Malignancy
• Trauma
• Stroke
• Sickle cell disease
• Superficial thrombosis
• Pre-eclampsia

There are also certain non-pathological cases that demand a D-dimer test to rule out clots and thrombosis. They are:

• Pregnancy
• Post-operative cases
• Cigarette smokers
• Elderly

There are also certain emergencies that require an immediate D-dimer report. When there is a suspected case of DIC or disseminated intravascular coagulation or a snake bite, you may need to undergo the test at once.

The D-dimer test requires the collection of a blood sample. This can be taken at any time of the day and does not require fasting.

Test Preparation

The test itself is rather simple and straightforward. The D-dimer blood test is not a fasting test and can be conducted at any time during the day. It is beneficial to mention any conditions or medication being taken prior to the test. The test itself only takes about five minutes and requires the collection of a blood sample from the arm. No special care is required following a D-dimer test.

Test Inclusions

A D-dimer report will only give you the value of D-dimer in the body. It does not include any other parameters. It is important to remember that the value or the D-dimer result only suggests the presence of clots and does not give any additional information on where the clot may be or how big. Other tests, including scans or ultrasounds, may be requested depending on what the results of D-dimer tests show.

Thrombosis, Pulmonary embolism, Stroke, Disseminated intravascular coagulation, COVID-19

A D-dimer report will usually give you a D-dimer value. This is what the D-dimer range looks like:

Here are certain important considerations when comparing D-dimer values:

• The normal D-dimer range is below 0.50mg/L.
• A reading of 0.50 or more indicates a positive result. There is no critical level, value or range in this test.
• D-dimer levels are expectedly higher in the elderly and their D-dimer values must be interpreted by a doctor.
• Higher levels in the D-dimer test are also likely in individuals who have rheumatoid arthritis.

Once you have your D-dimer results, it is possible to interpret them. Low or normal levels show the absence of any clotting disorder. When the results are on the higher side, it indicates the presence of a clotting disorder. However, it does not specify its kind or location. It is also important to remember that higher levels could also be from instances of recent surgery, heart conditions or pregnancy. When the readings are not within the normal range, further investigation is important to make an accurate diagnosis.

The normal values, parameters, and reference ranges of the test may vary from lab to lab. Please refer to the ranges mentioned in the report and consult a doctor to understand the interpretation of lab reports.