A superficial venous thrombosis is a blood clot in a vein that is close to the surface of the skin. A superficial thrombosis usually forms a firm lump, sometimes like a rope, under the skin. Often the skin is red and tender. The skin may look infected, but an actual infection is not common.
If the area around the clot has inflammation, it is called superficial thrombophlebitis, or simply phlebitis.
Blood clots in superficial veins usually are not serious. Home treatment is typically all that is needed unless the clots are very painful or uncomfortable.