- superficial thrombophlebitis (blood clot forming within superficial veins)
- deep venous thrombophlebitis (blood clot forming within deep veins)
Deep venous thrombophlebitis presents more swelling than superficial thrombophlebitis. Moreover, it poses higher health risk. Although the blood clot may not totally occlude the vein when it loosens it may form an embolus that can travel within the circulatory system, lodge in smaller vessels and block blood supply, such as those in lungs (see pulmonary embolism).
Word origin: Greek thrómbos (clot) + phlebitis