Patients sleep with sore and weak legs, the following common causes: 1, overwork: daytime work is too strenuous or participate in strenuous exercise, can lead to overworking of the muscles of both lower limbs, the muscles will have a sense of fatigue, while there is a large amount of lactic acid accumulation inside the muscle, can also cause the clinical symptoms of sore and soft, and even can not walk normally. The clinical symptoms can be relieved by massage, hot compresses and elevation of the affected limbs. 2. Lumbar diseases: severe lumbar spinal stenosis or lumbar disc herniation can stimulate and compress the nerves of the lower limbs, resulting in the loss of innervation of the muscles of the lower limbs, which can also manifest as clinical symptoms of soreness and weakness of the legs, accompanied by lumbar pain and restricted movement of the lumbar spine. CT examination or MRI examination can reveal the specific degree of lesion of the lumbar spine. 3, calcium deficiency or osteoporosis: calcium deficiency or osteoporosis can lead to pain in multiple bones throughout the body, soreness and weakness of the lower limbs, which should be ruled out by serum calcium ion examination and bone density examination. Sleeping legs appear sore and weak, must be early diagnosis, early treatment, to avoid serious consequences such as muscle atrophy of both lower limbs, to avoid affecting normal life and work.