Phlebitis is inflammation of a vein. The condition is characterized by tenderness, redness and hardness along the course of the vein. The cause of the inflammation may be injury or infection of the vein. Individuals with certain diseases such as systemic lupus erythematosus, vasculitis or malignancy are at increased risk of phlebitis. Diagnoses of this condition can be established by either a physical examination or ultrasound. The treatment of phlebitis is based on anticoagulant drugs or surgery.