What is hydronephrosis?

Hydronephrosis is characterized by the swelling of a kidney due to a buildup of urine, which occurs when there is a blockage in the urinary tract, specifically affecting the ureters. When urine cannot flow freely from the kidney to the bladder because of this obstruction, pressure builds up, leading to the dilation of the renal pelvis and calyces. This can result from various causes, such as kidney stones, tumors, or congenital abnormalities in the urinary tract.

The other options do not accurately describe hydronephrosis. A buildup of fluid in the lungs refers to pulmonary edema, which is unrelated. While kidney stones can lead to hydronephrosis, they themselves are not a direct definition of the condition. Liver function issues involve completely different physiological processes and organs. Understanding hydronephrosis is crucial for recognizing urinary tract issues and preventing potential kidney damage from prolonged pressure buildup.