Deep Vein Thrombosis

The Various Methods of Diagnosing a Deep Vein Thrombosis

Imaging tests such as an ultrasound are one of the most common methods of detecting a deep vein thrombosis, but there are also many other beneficial ways of diagnosing this condition. A deep vein thrombosis is a type of blood clot that can form in veins that flow deep within the body, and they most often occur in the legs. This type of clot can block blood flow and cause severe discomfort, but if it breaks off and travels into the lungs, it can cause a potentially life threatening pulmonary embolism. The only way to avoid the potentially fatal side effects of a deep vein thrombosis is to treat it before it becomes serious. Therefore, it is important to diagnose the thrombosis as soon as possible.

Deep Vein Thrombosis

Signs of a Deep Vein Thrombosis

The first step in diagnosing a deep vein thrombosis is typically a physical exam to see if the patient is exhibiting symptoms and signs of this health condition. The most common symptoms of a deep vein thrombosis is swelling or pain, especially if it occurs in a leg. The affected area may be tender to the touch, the skin might seem warm, and the area may look reddened. If a patient is showing these signs or the doctor has another reason to suspect a deep vein thrombosis, further testing will typically be done to confirm the diagnosis.


An ultrasound is a device that sends sound waves through your body, and then a computer translates these sound waves into a rough image of the tissues in your body. The blood clot can sometimes be visible in this test. Unlike other forms of imaging tests, an ultrasound does not require a huge, expensive machine, so this is often one of the first tests done to diagnose a deep vein thrombosis. Since this form of diagnosis is fast and noninvasive, it is often done repeatedly to see if the blood clot is moving or growing in size.

Blood Tests

Sometimes, doctors may be able to confirm a deep vein thrombosis diagnosis just by doing a simple blood test. Because the body is trying to dissolve the clot naturally, almost everyone with a deep vein thrombosis will have high levels of D dimer in their blood. This is a type of fibrin degradation product that is used to dissolve blood clots, and it can be detected with a simple lab test on a blood sample.

Imaging Tests

Both CT scans and MRI scans can provide a detailed visual picture of your veins. Therefore, they can show a blood clot that is hidden deep within the body. Often, deep vein thrombosis are diagnosed after a patient is undergoing one of these tests for an unrelated issue. These types of imaging tests are rarely used to diagnose a deep vein thrombosis, but they are often used to diagnose the pulmonary embolisms that can occur later on.


This test involves injecting a dye into one of the veins of your body. The dye flows through the veins and provides a contrast when an X ray is done. The combination of an X ray and the dye in your veins will produce a venogram that shows all of your veins. If there is any sort of blood clot, it will appear on the venogram. This method of diagnosis is usually only done if the blood clot is too small to show up in other tests like the ultrasound.