Leg pain at night after walking more during the day may be caused by lactic acid buildup, or compression of nerves by a herniated lumbar disc, or complications caused by vasculitis, which can be treated with general therapy, medication, physical therapy or surgery according to the cause. 1. Lactic acid accumulation: It is a normal reaction after activity, and excessive accumulation of lactic acid will cause pain. Appropriate massage and hot compresses can be used to relieve symptoms and promote lactic acid metabolism. 2. Herniated lumbar disc: When the herniated lumbar disc compresses the nerves and causes leg pain, it is necessary to insist on taking oral non-steroidal anti-inflammatory drugs for pain relief, such as celecoxib and ibuprofen. Those with serious symptoms can consider infrared physiotherapy, microwave physiotherapy, traction and so on. 3. Vasculitis: Some patients with vasculitis have serious conditions, and walking for a long time can easily cause leg pain. At present, it is necessary to pay attention to keep warm, prevent local cold air stimulation, severe symptoms can be oral vasodilator treatment, such as cilostazol, sagarrelate hydrochloride. If walking causes leg pain symptoms, lasts for a long time, or is difficult to relieve, it is recommended to go to the hospital for examination to clarify the cause of the disease, and then carry out treatment.