Long walks with leg pain may be caused by the following reasons: 1. There may be a case of overexertion. There are many patients who walk long distances without realizing it, or take flat walks for exercise. This may cause fatigue in the muscles of the lower extremities over time, resulting in pain in the legs. 2. It may be caused by joint lesions in the lower extremities. The knee and hip joints of the lower extremities may suffer damage to the internal structures of the joints, such as joint cartilage, meniscus, ligaments and so on, after a long period of walking activities. Once this happens, it may also cause pain in the entire lower limb. 3. Intermittent claudication may exist. This type of patient is often due to the presence of occupational lesions in the spinal canal or vascular lesions in the lower extremities, resulting in significant pain in the lower extremities and weakness after walking for a period of time. If the patient sits down or lies down to rest for a while and then continues walking, the symptoms will disappear or be relieved significantly.