Kidney stones can be one of the most painful experiences of your life. The best types of physicians to see for hydronephrosis is primary care physician or, in severe cases, kidney doctor or urologist. Urine flows from the kidneys down the ureters into the bladder and out the urethra. When kidney stones get stuck in the ureter, they prevent flow from the kidney to the bladder. This causes urine to back up and fill spaces in the kidney. When this happens, we call it hydronephrosis. Hydronephrosis, if left for long enough, can cause kidney failure. Most of the time it resolves on its own after the kidney stone has been removed. The long-term implications depend on its severity.