What is deep vein thrombosis? Deep vein thrombosis (also called
DVT) is a blood clot in a vein deep inside your body. These
clots usually occur in your leg veins. While DVT is a fairly
common condition, it is also a dangerous one. If the blood clot
breaks away and travels through your bloodstream, it could block
a blood vessel in your lungs. This blockage (called a pulmonary
embolism) can be fatal. Written by familydoctor.org editorial
staff