Low temperature of the right leg may be due to physiological and pathological reasons, such as venous thrombosis of the lower extremities and thromboembolic vasculitis. 1. Physiological reasons: low temperature of the right leg may be that it is not well kept warm, for example, some people’s pants will have a torn look. When the temperature is low, it will make the person have the feeling of cold legs. 2. Pathological causes (1) Lower extremity venous thrombosis: prolonged bed rest, prolonged sitting, little limb activity or blood in a state of hypercoagulability, etc., make the blood vessel wall prone to thrombosis. When the thrombus blocks the vein of the right leg, it causes poor blood flow in the blood vessel, and low temperature of the right leg will occur. (2) Thromboembolic vasculitis: it may be closely related to smoking, heredity, cold stimulation, male hormone, blood hypercoagulable state and so on. When thrombo-occlusive vasculitis occurs in the right leg, causing ischemia of blood vessels, low skin temperature will occur, which may also be accompanied by pain and pressure pain. When the temperature of the right leg is low, excluding physiological factors, it is recommended to consult a doctor in a timely manner, follow the doctor’s instructions for further examination, clarify the cause with the help of the doctor, and carry out targeted treatment or therapy.