Phlebitis means inflammation of the vein. Phlebitis can occur in superficial, varicose veins or in deep veins. Patients typically get phlebitis in their legs. The inflamed vein may cause blood clots to form. This is called thrombophlebitis. When phlebitis occurs in deep veins, it is called deep vein thrombophlebitis. Deep vein thrombophlebitis is dangerous and potentially life threatening because the blood clots in the deep veins, called deep vein thrombosis (DVT), could end up breaking off and traveling to the lungs. While superficial phlebitis is rarely dangerous, if left untreated, it could lead to the development of dangerous deep vein thrombophlebitis and DVT.
The cause of superficial phlebitis is unclear. Patients may develop phlebitis after a procedure. It can also develop from a trauma to a preexisting varicose vein.