A Guide to Deep Vein Thrombosis

Deep vein thrombosis (DVT) is a vascular condition which results in a blood clot forming in a deep vein (such as the ones found in the leg). Read on to learn more about DVT.


In many cases, DVT does not cause any noticeable symptoms. However, if the blood clot that has formed is particularly large, it may make the skin of the affected leg feel very warm to the touch. The affected leg may also be very red, swollen and tender.


There are several things which can lead to a person developing DVT. These include vein trauma (caused by, for example, a person injuring their leg), blood-clotting abnormalities which make the blood thicker, or a reduction in blood flow through the veins (this can occur if a person is bedridden or spends a lot of their time sitting down).


An ultrasound machine is normally used to diagnose DVT. This equipment can be used to visually identify the clot and to determine the speed at which blood is flowing through the affected vein.

If the results of the ultrasound are inconclusive, the doctor may have a 'D-dimer' blood test carried out; if this test indicates that the patient has high levels of 'D-dimer' in their system, then they probably have DVT.

In instances where neither the blood test nor the ultrasound results provide enough evidence to diagnose a person with DVT, their doctor may have a 'venogram' done; this involves injecting a dye into the person's veins which will increase their veins' visibility when their leg is X-rayed. The dye can help to determine the precise location of the blood clot.


DVT must be treated; if it is not, it can lead to a very serious, potentially life-threatening condition called a pulmonary embolism (where a blood clot ends up travelling to the lung).

In most cases, people who have been diagnosed with DVT are given an injectable or oral medication called an anticoagulant, which can prevent the blood clot from growing in size and completely blocking the flow of blood.

However, if a patient's existing health problems mean that they cannot take anticoagulants, a vascular surgeon may then fit a vena cava filter inside the vena cava vein. This device captures blood clots in the leg before they can start moving towards the lungs.

The insertion of a vena cava filter is relatively straightforward and can be completed by a skilled vascular surgeon in less than an hour. Most people recover from this procedure very quickly and only need to spend one night being monitored before they can go home.