What condition involves inflammation of the renal pelvis and kidney?

Pyelonephritis is characterized by inflammation of the renal pelvis and kidney, typically resulting from a bacterial infection that has ascended from the lower urinary tract. This condition can lead to symptoms such as fever, chills, flank pain, and urinary symptoms like dysuria or increased frequency. The inflammation primarily affects the kidney's tissues and structures, which can impact kidney function if not treated promptly. The distinction of pyelonephritis is its specific involvement of both the renal pelvis and the kidney parenchyma, setting it apart from other nephritic conditions.

Other conditions mentioned, such as nephritis in general, may refer to inflammation of the kidneys but do not specifically denote the involvement of the renal pelvis. Glomerulonephritis is a specific type of nephritis that primarily targets the glomeruli, the filtering units of the kidneys, and may not involve the renal pelvis. Interstitial nephritis can involve inflammation but typically refers to the kidney's interstitial tissue rather than the renal pelvis specifically. Thus, pyelonephritis is the correct term for the condition that affects both the renal pelvis and the kidney.