Left calf intermuscular vein thrombosis refers to the formation of blood clots in the inner wall of the veins of the lower limbs that attach to the walls of the tubes due to trauma, hypercoagulability, and prolonged bed rest. The left calf intermuscular vein belongs to the deep vein branches of the lower extremity, which are prone to thrombosis when the veins are damaged, the blood flow is slow, or there is a state of hypercoagulability of the blood. Vascular injury can cause the release of biologically active substances in the body, initiating the endogenous coagulation system, and changes in the charge of the vein wall, leading to platelet aggregation, adhesion, and thrombus formation. Prolonged bed rest or post-surgical lower limb braking can cause slow venous blood flow in the lower limbs, forming eddies in the valvular sinus, resulting in localized valvular hypoxia, causing leukocyte adhesion and promoting thrombosis. Pregnancy, postoperative trauma, long-term application of contraceptives, etc., can increase the platelet count, increase the content of coagulation factors, abnormal clotting of blood in the lower extremity blood vessels, the formation of thrombus. Left calf interosseous vein thrombosis, it is recommended to consult a doctor in time, under the guidance of professional doctors, standardized treatment, to avoid thrombus dislodgement.