Weakness of the lower limbs may be caused by peripheral neuropathy, osteoarthritis of the lower limbs, osteoporosis, wasting muscle atrophy and other diseases. 1. Peripheral neuropathy: If the patient suffers from spinal cord cervical spondylosis or lumbar intervertebral disc herniation, the weakness of both lower limbs will occur due to the lesion occupying the position in the vertebral canal, thus compressing the spinal cord and nerve roots. In the case of severe lesions, numbness and pain in the lower limbs will occur. 2. Osteoarthritis of the lower limbs: Osteoarthritis refers to the inflammation of the bone part of the joint, which will be manifested as inflammatory pain. When both lower limbs are inflamed at the same time, weakness and pain in the lower limbs will occur. 3. Osteoporosis: Osteoporosis is a common disease among the elderly, and its early typical manifestation is obvious fatigue or widespread pain in the whole body. In addition to the elderly, there are also patients with pathologic osteoporosis. When both lower limbs are suffering from osteoporosis, the symptoms of weakness of both lower limbs will be shown. 4. Wasting muscle atrophy: Wasting muscle atrophy is more common in long-term bedridden and sedentary people, and is caused by muscle inactivity. Once the patient suddenly move, will feel the lower limb muscle strength is insufficient, that is, manifested as lower limb weakness. If the lower limb weakness excludes physiological causes and is not relieved and worsens over a long period of time, it should be taken seriously. It is recommended that patients go to the hospital for a comprehensive examination in a timely manner, and based on the results of the examination, effective cause-specific treatment should be carried out.