The most common cause of superficial thrombophlebitis is?

Venous thrombosis occurring in superficial veins is called superficial venous thrombosis Most common cause of superficial vein thrombophlebitis is the canulation of the vein for intravenous infusion. Other impoant causes of superficial vein thrombophlebitis are -- Varicose veins Pregnant or postpaum women Thromboangitis obliterans or Buerger's disease. Symptoms - Erythema, induration and tenderness along the superficial vein. Over a time a firm tender cord develops. The patient complains of localized extremity pain and tenderness