The main causes of leg pain after waking up are the following: 1. It may be due to strenuous activity or excessive labor during the day, resulting in long-time muscle spasms and tension in the legs. This is often the case. 2, not except for the pain caused by low calcium or hypokalemia in the body, which is particularly common in young people or adolescents at the stage of growth and development, should be supplemented with a large amount of calcium and potassium, the symptoms of leg pain can be relieved. 3, elderly diseases, such as lumbar disc herniation or Lumbar spine osteophytes, or even lower limb venous disease, can lead to the phenomenon of local leg soreness after waking up. Therefore, in this case, you should go to a specific specialist or hospital for a detailed examination to find the exact cause of the disease and to carry out symptomatic treatment.