The symptoms of pain in the left leg may be due to the following reasons: 1. The soft tissues of one leg are repeatedly contracted and stretched due to prolonged posture, repetition of a certain action, and excessive strenuous exercise, resulting in local congestion and edema, forming sterile inflammation, generating muscle fatigue, and the accumulation of acidic products leading to painful symptoms in the leg. 2. The most serious ones are local septic infectious diseases of the leg, malignant tumors, and local soft tissue destruction or even bone destruction caused by lumbar disc herniation. 3.It may be caused by lumbar disc herniation, after the lumbar disc herniation compressing the nerve root, the area dominated by the nerve root produces radioactive pain, soreness and swelling, often accumulating one side of the leg. 4.If there is an obvious history of trauma, it may be due to trauma leading to local soft tissue damage and bone damage in the left leg. If there is a clear history of trauma, it may be caused by trauma to the local soft tissue of the left leg as well as bone damage, it is necessary to actively improve the examination to clarify the severity of the injury, so as to choose a reasonable treatment method to get timely and effective relief of the symptoms of left leg pain.