There are several possible reasons for the weakness of the legs: first, kidney deficiency, when the kidneys are weak, there can be weakness of the lower extremities, pain in the waist and knees, then the diagnosis of Chinese medicine pulse, if necessary, the treatment of kidney medicine. Secondly, ion deficiency, such as low calcium or low potassium, can also appear in the weakness of the lower extremities, to carry out blood tests, if necessary, potassium and calcium supplementation treatment. Third, cervical spondylosis, when cervical spondylosis compresses the spinal cord, the symptoms of weakness of both lower limbs can appear, which can be accompanied by walking disorders, such as the feeling of stepping on cotton when walking, and then the diagnosis should be made by cervical spine nuclear magnetic examination. Fourth, lumbar disc herniation, if the lumbar disc herniation is serious, resulting in lumbar spinal stenosis, then walking weakness can occur, and the diagnosis and treatment should be carried out by nuclear magnetic and CT examination of the lumbar spine.