Caption: Thromboembolism
Text: Blood clots in the veins in the legs (Deep venous thrombosis or DVT) can block return of blood from the leg and cause swelling and pain. In addition, fragments of these blood clots can break loose and travel with returning venous blood to the heart and then to the pulmonary arteries that send blood to the lungs. This "thromboembolism" can become lodged in one of the main pulmonary arteries or in one of its tributaries and cause severe shortness of breath and even death.