The renal papillae are the areas of the kidney where the openings from the collecting ducts enter the renal pelvis. Necrosis (tissue death) of this area may result in impairment of the kidneys ability to concentrate the urine with ensuing polyuria (increased urine volume usually in excess of 3 liters/day) and nocturia (frequent urination at night).

The necrotic tissue may be sloughed off, and it may be present in the urine as tissue, or the tissue may obstruct the renal pelvis or the ureter causing obstruction. Presence of necrotic tissue in the urine increases the risk of urinary tract infections. Necrosis of multiple papillae in the kidney can lead to eventual failure of that kidney.

Renal papillary necrosis is most commonly associated with analgesic nephropathy, diabetic nephropathy, renal transplant rejection, urinary tract obstruction, kidney infections and sickle cell anemia. Sickle cell anemia is a common cause of renal papillary necrosis in children.