Inner leg pain may be caused by physiological reasons such as overwork, or by pathological reasons such as trauma, fasciitis, infection and tumor. 1. Overwork: Lactic acid accumulation within the inner thigh due to physiological reasons such as overwork can cause inner leg pain. 2. Trauma: due to trauma and other violent factors leading to fracture of the inner leg, local soft tissue injury or even nerve injury, patients may experience pain, swelling and impaired movement of the inner leg. 3. Fasciitis: chronic aseptic inflammation of the inner leg muscles, fascia and other tissues caused by long-term strain, patients may experience inner leg pain. 4. Infection: due to bacteria and other pathogens infecting the inner thigh, causing localized purulent changes and stimulating the peripheral nerves, patients may experience pain on the inner side of the leg. 5. Tumor: Due to the occurrence of tumors on the inner side of the leg, such as soft tissue tumors, bone tumors and other diseases, squeezing the surrounding tissues, the patient may have the symptom of pain on the inner side of the leg. There may be other reasons for the pain on the inner side of the leg, so it is recommended to consult a doctor in time to clarify the cause of the disease and carry out targeted treatment or therapy with the help of a doctor.