Blood clots can be a problem after many kinds of procedures, including back surgery. The condition is called deep venous thrombosis (DVT). In DVT, blood clots form in the veins of the legs, blocking the normal blood flow. This makes the area become swollen and sore. If the clot doesn't break up, it can damage that area of the leg. If the clot breaks loose and travels to the lungs, it can get stuck. This cuts off blood supply to a section of the lung and causes a pulmonary embolism. In a pulmonary embolism, part of the lung collapses. You can die from a pulmonary embolism.

The good news is that there are several steps you can take to help avoid DVT. Your doctor will give you drugs that make the blood less able to clot. There are several different kinds of medications that work against clots.

You can also try different kinds of support stockings. Pulsatile stockings inflate like a blood pressure cuff to squeeze the veins in your leg. Wearing a special stocking called TED hose also helps squeeze the veins to help prevent formation of a clot.

The best strategy for avoiding blood clots is to get moving as soon as possible after surgery. Blood that is moving has a harder time forming a clot. Even if you need to stay in bed, you can move your feet. Pump your feet up and down throughout the day. This gets the muscles working and the blood moving in your whole lower leg. Try to stand and walk as soon as your doctor gives the OK.