In the GU system, which finding is most indicative of potential kidney involvement and is localized over the costovertebral angle?

• A. Renal angle tenderness
• B. Flank tenderness
• C. Kidney tenderness
• D. CVA tenderness

Answer: (D)

The key idea is that tenderness at the costovertebral angle signals kidney involvement. The costovertebral angle is the area where the lower rib meets the spine; when a clinician percusses or taps this region, pain suggests inflammation or infection of the kidney, such as pyelonephritis. This sign is particularly useful because it localizes the problem to the kidneys, unlike general back or flank tenderness which can come from muscles or other structures. To elicit it, the examiner uses a blunt percussion over the CVA; pain on tapping indicates CVA tenderness. In contrast, flank tenderness is less specific and can arise from non-renal causes, so CVA tenderness is the more definitive indicator of kidney involvement.