Topic overview

Start with the big picture

Urinary tract infections are microbial infections of the urinary tract; dysuria and frequency without vaginal discharge are clues that support cystitis, while fever, flank pain, costovertebral-angle tenderness, and white blood cell casts point toward pyelonephritis. The lesson also introduces common pathogens and host risk factors. For urolithiasis, it reviews stone types, risk factors, imaging characteristics, and the presentation of renal colic. The renal failure section introduces acute kidney injury, its prerenal, intrinsic, and postrenal categories, and the use of fractional sodium excretion to help assess cause. Together, these clinical correlates provide a framework for recognizing urinary-system disorders and understanding their initial evaluation and management.