What is deep vein thrombosis? — DVT is blood clots in the deep veins of the leg. Deep vein thrombosis, or "DVT" for short, can be dangerous.
If a blood clot forms inside a blood vessel, it can clog the vessel and keep blood from getting where it needs to go. When that happens to one of the veins deep within the leg, blood can back up and cause swelling and pain. Another problem with blood clots in veins is that they can travel to other parts of the body and clog blood vessels there. Blood clots that form in the legs, for example, can end up blocking blood vessels in the lungs. This can make it hard to breathe and sometimes, when they are large, can lead to death. When blood clots travel to the lungs surgeons call it "pulmonary embolism" or "PE."
Sometimes clots form in the veins that are closer to the surface of the skin, called the superficial veins. Those blood clots cause a different set of symptoms. Blood clots in the veins near the surface of the skin are more painful and cause redness or infection. These clots sometimes also cause the veins to harden and bulge into ridges that look like cords. This is most common with the veins below the knee. If you think you have a blood clot in your leg, call your doctor right away. Blood clots in the veins near the surface of the skin are less dangerous. But blood clots in the deep veins of the leg are more serious.
If you get any of these symptoms, especially if they happen over a short period of time call 000 immediately.