Consequences that may be induced by severe hydronephrosis caused by kidney stones are: renal atrophy, co-infection and so on. 1. Renal atrophy: when kidney stones cause severe hydronephrosis, due to the large amount of urine stagnation in the renal pelvis, the renal parenchyma is severely compressed, and long-term compression can lead to cortical atrophy of the kidney on the affected side, which in turn can seriously damage the function of the kidney on the affected side. 2. Combined infection: severe hydronephrosis is very easy to be combined with urinary tract infection, the patient will have fever, lumbar pain, bladder irritation and other signs of infection, especially due to the distal ureteral stone obstruction, the infected urine reflux back to the kidneys, a large number of bacteria through the kidneys into the systemic circulation can be induced by systemic infections and even infectious toxic shock, which can be a serious threat to the patient’s life. It is recommended that patients with severe hydronephrosis caused by kidney stones go to the hospital as soon as possible to relieve the urinary tract obstruction and drain the urine in a timely manner.