Weakness of the right leg is considered to be related to strain, lumbar spondylosis, neurological diseases and other reasons. 1. Strain injury: such as walking too much, overwork, etc., will cause muscle fatigue, at the same time, the acidic product secretion increases, and cause leg weakness. 2. Lumbar spondylosis: for example, lumbar disc herniation, lumbar spinal stenosis, etc. These lesions will cause compression and stimulation of the nerves, which will cause pain, numbness, weakness and other symptoms in the lower limbs, and will also cause weakness in the right leg. 3. Neurological diseases: such as cerebral infarction, cerebral hemorrhage, etc., these diseases can cause nerve damage, causing nerve dysfunction, which can also cause right leg weakness. There are other causes of right leg weakness, such as knee joint disease, electrolyte deficiency, etc., you should go to the hospital in time to further identify the cause of the disease, and then targeted treatment.