Thrombophlebitis is defined as thrombotic inflammation of a previously healthy superficial vein, varicophlebitis as that occurring in varicosities. The latter appears responsible for the majority of thrombotic venous occlusions. In contrast to venous thrombosis, the thrombotic involvement of deep veins, thrombophlebitis usually resolves without sequel and, in general, thrombophlebitis nor varicophlebitis are associated with the risk of pulmonary embolism. The clinical presentation of thrombophlebitis is that of a tender, hardened superficial vein which, in the presence of inflammation, may be very painful. The lower extremities are most frequently involved. Differential diagnostic considerations include bacterial cellulitis and lymphangitis. The cause of thrombophlebitis, which is rare without precipitating factors, may be a mechanical lesion such as kinking of the vein or trauma to the wall of the vein as well as other primary disease such as auto-immune afflictions, endangiitis obliterans or malignancy; in particular, with localization in the area of the rump, with concomitant occurrence in various regions or extending phlebitis, paraneoplastic syndromes and hemoblastoses should be ruled out. Rarely, phlebitis may be associated with tuberculosis and syphilis. Thrombophlebitis may be caused iatrogenically by improper application of chemical substances which cause damage to the venous walls as well as by indwelling catheters or cannulas. This form can progress to sepsis and pulmonary embolism may be incurred. Varicophlebitis, in contrast, accounts for about 90% of all cases of phlebitis and can be regarded as a typical late complication of varicosities in the superficial venous system.(ABSTRACT TRUNCATED AT 250 WORDS)