Phlebitis is inflammation of a vein, usually in the leg. It can happen with or without a clot, but the common theme is pain, redness, and swelling along the course of the vein. Pain is the first clue. It feels like a deep, burning ache or tenderness along the vein, especially when you press or flex the muscle. Redness and warmth follow. The skin over the vein turns red or pink and feels hot to the touch, like a localized sunburn. Swelling shows up. The area around the vein puffs, and socks leave a tight groove that takes time to... Learn more