In this case study, a collegiate lacrosse athlete, “Noah,” develops unusual fatigue, muscle pain, edema, and dark-colored urine. Concerned, the athletic trainer conducts a urinalysis, which suggests impaired kidney function, and Noah is diagnosed with rhabdomyolysis. As students work through the case, they investigate possible causes and, in the process, gain a stronger understanding of kidney function and urine formation while exploring normal urine contents, glomerular filtration rate, and nephron anatomy. The case also provides a significant review of the relationship between hydrostatic pressure, colloid osmotic pressure, and glomerular filtration. Designed for undergraduate anatomy and physiology students and exercise physiology students, the case can be completed in a single 75-minute class period, or in 50 minutes if the first two sections are assigned as pre-class homework or if class discussion is shortened. A pre-class preparation handout (see Supplemental Materials) is available to help students review major concepts before beginning the case.