Thrombotic superficial phlebitis is a thrombotic inflammation of the visible veins located on the body surface. The clinical manifestations are redness, swelling, heat, pain, striae or hard nodules along the superficial veins, and pain to palpation, which is a common clinical condition. I. Etiology: Thrombotic superficial phlebitis of the extremities can be caused by different reasons. Clinically, it can be divided into three categories: ① superficial phlebitis caused by chemical stimulation, intravenous injection of various irritant solutions, such as hypertonic glucose solution, various antibiotics, hydrocarbon agent, organic iodine solution, etc., can cause chemical irritation in the superficial vein lining of the injected vein, resulting in more extensive damage, rapid thrombosis, followed by a significant inflammatory reaction on the surface. ②Catheter for continuous infusion, often can make the vein wall suffer direct damage, resulting in thrombosis and rapid inflammatory reaction, commonly in large burns, severe trauma and major surgery and other critical patients. When varicose veins of lower extremities, whether they belong to the great saphenous vein or the genus branch of the small saphenous vein, due to venous blood stagnation, the skin of the foot and boot area is often subjected to chronic infection due to nutritional changes, which can cause the varicose veins to suffer from hypoxia and inflammatory damage, leading to thrombotic superficial phlebitis. Second, the symptoms superficial veins of the affected limb suddenly show the cords or columnar, reticular swelling, the lesion venous tissue is red or edematous, local skin temperature is elevated, feel and heat, tenderness and pressure pain is obvious, limb movement is limited, the systemic reaction is often light, slight heat discomfort, after rest or treatment, the red heat swelling gradually subsides, left with dark brown or dark red pigmentation, superficial venous cords or hard knots or bead-like changes are obvious, usually 2 ～Tenderness usually disappears completely in 2 to 3 weeks. If the varicose veins are caused by varicose veins, or in the case of obvious trauma, the above symptoms gradually appear and the venous striae and sclerotia do not subside for a long time, they are often cured by surgical elimination. If the veins of the limbs are caused by indwelling tubes, the patients often have chills and fever of 38-40℃ first, then the veins of the indwelling tubes are red, swollen, hot and painful or only have diffuse swollen areas, and when the tubes are removed, they often lead to pus or pus and blood, and the clinical systemic symptoms of this type of patients are heavier than the local ones.