What is a key symptom of pyelonephritis?

CVA tenderness, or costovertebral angle tenderness, is a key symptom of pyelonephritis, which is a type of kidney infection. This tenderness is typically assessed by gently tapping the area on the back just below the ribs, where the kidneys are located. If a patient has pyelonephritis, this action often elicits pain due to inflammation and infection of the renal tissue. This symptom is significant for differentiating pyelonephritis from other conditions that may present with abdominal or flank pain.

The other symptoms listed relate to different conditions. Scant urethral discharge is more characteristic of urethritis or sexually transmitted infections. Lower abdominal pain can be seen in various abdominal or pelvic issues, not specific to pyelonephritis. Red, swollen testes are indicative of conditions like orchitis or epididymitis. Therefore, CVA tenderness stands out as a clinical hallmark for pyelonephritis, highlighting its specific relationship to renal pathology.