Hydronephrosis

**Definition:** Abnormal enlargement or swelling of a KIDNEY due to dilation of the KIDNEY CALICES and the KIDNEY PELVIS. It is often associated with obstruction of the URETER or chronic kidney diseases that prevents normal drainage of urine into the URINARY BLADDER.

**Tree numbers:** - C12.050.351.968.419.307 - C12.200.777.419.307 - C12.950.419.307