There are several reasons for stiffness in the legs: 1, if the patient has been in a cold or damp environment for a long time, or has been cold or chilled, such as sleeping with a thin quilt that does not provide enough warmth, it will lead to stiffness in the legs; 2, when the patient has been doing heavy physical labor for a long time and cannot get enough rest, the amount of exercise for a long time will cause lactic acid to accumulate, and muscle spasm will occur, and in severe cases, stiffness may occur 3, when the patient has a disease in the legs, such as deep vein thrombosis in the lower extremities, which can lead to impaired blood circulation in the legs, the phenomenon of leg stiffness may also occur; 4, when the patient has had a traumatic injury, such as fracture recovery process is not very good, no functional exercise, the phenomenon of leg stiffness may also occur; 5, if the patient has a brain disease, such as stroke, may appear morning The phenomenon of stiffness, which usually occurs in the morning to keep 1-2 hours, may also occur in the legs.