Bad kidney can lead to low back pain, but low back pain caused by bad kidney is mainly back and knee pain, weakness and loss of appetite, the reason is pain caused by decreased glomerular filtration rate, kidney edema and tension in the envelope, so when patients have low back pain, they cannot blindly think that the kidney is bad. It is necessary to further improve the relevant examination to investigate the cause of low back pain, for example, lumbar disc herniation can cause low back pain and restricted bending, which can be further investigated by CT or MRI of lumbar spine. Lumbar muscle strain can also cause low back pain, which can be recovered through rest or rehabilitation exercises. Sudden pain can cause symptoms of digestive system, nausea, vomiting, and even the patient has the urge to stool, but can not solve the stool in the toilet.