Hydronephrosis occurs when urine builds up in the kidneys and cannot drain out to the bladder. The kidneys swell from the excess urine. The condition may affect one kidney or both. Hydronephrosis is not a disease itself, but rather a sign of another disease or condition affecting the kidneys. Swelling of the kidneys can lead to kidney damage.
This is a serious condition that requires care from your doctor. Most patients who have hydronephrosis will not know it until it has already damaged the kidney. Therefore, if you are at risk for this condition, it is important to be under the care of a physician.