Thrombophlebitis is an inflammation of a vein due to a blood clot. The term comes from a combination of thrombus, meaning blood clot, and phlebitis, meaning inflammation or infection of a vein. When blood clots form, they release a number of toxic chemicals that cause inflammation of the vein.
Thrombophlebitis is classified as either superficial or deep. Deep thrombophlebitis is often called deep vein thrombosis (DVT). This condition is less common but more worrisome than superficial thrombophlebitis. Superficial thrombophlebitis is commonly seen in varicose veins and after insertion of intravenous (IV) tubes in the veins of the arms. Most cases of superficial thrombophlebitis resolve without any medical treatment.