What is deep vein thrombosis? how can a clot kill you?

Blockage in a vein: Clot or "solid blood" occurs when proteins change within the liquid blood. It can occur in the venous and/or the arterial circulation. Arterial clots can cause death by blocking vital arteries in the heart and or brain. Venous clots can cause death when they are large enough and travel to the lungs, as a pulmonary embolus, blocking the blood flow through the lungs.

A blood clot: There are deep and superficial veins in your legs. If you get a blood clot in one of your deep veins, some of the clot can break off and travel to your heart or lungs. If a blood clot that travels to your lungs is big enough, it can totally shut down blood flow to your lungs which means that your body gets no oxygen and that can kill you.