The processes by which the body repairs injured tissue result in an inflammatory reaction. Who is not familiar with the signs of inflammation around a scratch or cut? Redness, increased warmth, swelling and tenderness announce the active cellular reactions occurring around an injury. The scratch will heal with regeneration of normal skin, leaving no trace of the injury. The cut will eventually heal, replacing the injured area with a tough, fibrous tissue that leaves a scar.
The response of veins to injury occurs in a predictable fashion. Inflammation of a vein (phlebitis) tends to promote the local clotting of blood (thrombosis). Initial clotting in a vein, conversely, induces an inflammatory reaction. Therefore, the term thrombophlebitis is generally appropriate clinically since these two conditions typically occur together.
As with any body tissue, veins react to injury, be it from trauma, infection, or noxious chemicals. The resulting inflammation in a relatively superficial vein can be detected by a red, tender, and warm area over the skin. Probably the more common presentation is of a diffuse area of inflammation without streaking.
The inflammation caused by injury to veins tends to cause clotting of blood, particularly within the pockets of the valves. When clotting occurs, the thrombus obstructs venous drainage. The limb typically becomes swollen. It may feel firmer and have a dark red or bluish cast from stagnated and partially deoxygenated blood. The affected vein, if superficial, may be palpable; it is often described as “cord-like.”
Thrombophlebitis can occur and yet be completely “silent.” That is, it may produce no symptoms and may exhibit no signs of either blood clot or inflammation. Thrombi in the deep veins are notorious for producing minimal or no symptoms. This form of thrombophlebitis is not easily recognized and therefore often not treated. It is the form which has earned a great respect by clinicians in their high-risk patients.
Thrombophlebitis is an acute illness which generally lasts from one to several weeks. It usually involves the legs, with the calves by far the more likely site. When it occurs in a superficial vein, the signs are generally quite obvious. If in the deep veins, the clinical markers can be quite obscure. Sometimes, both superficial and deep veins are affected at the same time. More rarely, thrombophlebitis affects the arms, the chest wall, and the breast. No vein, in fact, is exempt. Sites other than the leg, however, are uncommon. When unusual or multiple sites are involved, cancer is suspect, barring some more obvious explanation such as local trauma. Whether or not a first episode of thromboembolism without apparent cause warrants an extensive evaluation for cancer has not been determined .