Back swelling after hydronephrosis may be because the condition has become serious, in addition to other diseases such as lumbar disc herniation, lumbar muscle strain, etc. may also appear back swelling. If the condition of hydronephrosis is more serious, the patient is likely to suffer from lumbar distension, lumbar pain or lumbar soreness, etc. Therefore, lumbar distension after hydronephrosis may be a sign that the condition has become serious. In addition, lumbar disc herniation, lumbar osteoarthropathy, lumbar muscle strain and many other diseases may also cause lumbar distension. Regardless of whether you are suffering from hydronephrosis or lumbar distension, it is recommended that you go to the hospital in time for further examination to clarify the cause of the disease, and then go through standardized treatment under the guidance of a professional doctor, so as to avoid delaying your condition.