Muscle soreness may be caused by lactic acid buildup, muscle spasm, etc. The specific recovery time cannot be judged, generally muscle soreness caused by lactic acid buildup can be recovered in 3~5 days, while muscle spasm patients need a few days to a few months due to different conditions. 1. Lactic acid accumulation: When patients who lack physical exercise for a long period of time suddenly engage in prolonged and strenuous exercise, lactic acid cannot be fully metabolized and accumulates in the body, causing muscle soreness. Generally, it can be recovered gradually without special treatment, and it usually takes 3~5 days to recover. Appropriate aerobic exercise or hot packs, massage, etc., sore muscles can shorten the recovery time. 2. Muscle spasm: Cold stimulation, high fever, epilepsy and other diseases or excessive loss of calcium ions can cause muscle spasm and muscle pain. If it is not caused by diseases such as cold stimulation, it can be treated by traction, and the spastic muscles can be recovered, and the general symptoms can be relieved quickly. If the symptoms are caused by a disease such as high fever or epilepsy, treatment for the primary disease is required and may take several days to several months. If the symptoms are not relieved within 3~5 days or accompanied by other obvious symptoms, patients with muscle pain should go to the hospital for diagnosis and treatment in time to avoid delaying the condition.