What is Involved in Making a Diagnosis of Deep Vein Thrombosis?

In order for a doctor to make a diagnosis of deep vein thrombosis, or DVT, he or she typically must perform a variety of tests, as the symptoms can be similar to those of numerous other conditions. The first step is typically gathering the patient's medical history to determine if he or she has any risk factors for DVT. A physical exam is then usually performed to see if the patient displays any signs of a clot. If there is an indication that a DVT may be present, the doctor will then normally order further tests such as an ultrasound or venography to confirm it.

To get to a diagnosis of deep vein thrombosis, a person's doctor will first gather information to see if that is likely to be the cause of his or her symptoms. The doctor will review the patient's overall health and any recent medical treatments that he or she has had, such as surgery or cancer treatment. It will also be important to review any medications the patient is taking that could increase the likelihood of a clot forming.

A physical exam is the next step toward making a diagnosis of deep vein thrombosis. Patients will typically have their blood pressure, heart, and lungs checked for any issues. The doctor will also look for any physical signs that could indicate a blood clot, such as swelling or discoloration on the affected leg, noticeable veins on the surface, or fatigue in the leg. If the physical exam indicates that the patient likely has a DVT, the doctor will then usually order further diagnostic tests that can confirm the presence of a clot.

There are several different tests that may be used make the diagnosis of deep vein thrombosis. Perhaps the most common is an ultrasound, where sound waves are used to create images of the patient's veins and hopefully locate a clot. This test may not be sensitive enough to find very deep clots, however, in which case the doctor may turn to a venography; this procedure involves injecting a radioactive dye into the veins so they can be seen more easily in an X-ray. Another option is a D-dimer test, which can detect high levels of a substance in the blood which can indicate a clot in the body. Magnetic resonance imaging (MRI) or computed tomography (CT) scans are also sometimes used to give a clearer picture of the patient's veins when other methods are inconclusive.