Phlebitis is the inflammation of a vein, often occurring in the legs. It can be caused by various factors, including injury, infection, or prolonged inactivity. Symptoms may include redness, swelling, warmth, and pain along the affected vein. There are two main types of phlebitis: superficial and deep. Superficial phlebitis affects veins close to the skin's surface, while deep vein phlebitis, or deep vein thrombosis (DVT), involves deeper veins and can lead to serious complications. Treatment typically involves pain relief, compression, and sometimes medications to reduce inflammation or prevent blood clots.