Phlebitis refers to inflammation of the vein walls, characterized by pain, redness, tenderness, swelling, and induration in the absence of thrombus. This may be due to medication use, a procedural treatment, a medical device, or, less frequently, infection. A common cause of infusion phlebitis is a complication of inserting a peripheral intravenous cannula for administering intravenous fluids and medications, which may provide opportunity for postoperative infection and fever.

Superficial phlebitis occurs typically in the superficial veins of the lower extremities. Phlebitis may be associated with varicose veins, vein trauma, venous stasis, superficial thrombophlebitis, Behçet syndrome, thromboangiitis obliterans (Buerger disease), and Mondor syndrome.

Treatment is geared toward alleviating symptoms and preventing thrombus formation and movement into the deep venous system.