Costovertebral angle tenderness

Transverse section, showing the relations of the capsule of the kidney.

Image of a human back

Kidney punch or CVA Tenderness is elicited when gently tapping the area of the back overlying the kidney producing pain in people with an infection around the kidney (perinephric abscess) or pyelonephritis or renal stone. Since the kidney lies directly below this area, known as the costovertebral angle, tapping disturbs the inflamed tissue causing pain.

This medical test was first described by the American surgeon John Benjamin Murphy.^[1][2][3]

References

1. ^ Oh, Timothy T.; Schmitz, Robert L. (1993). The Remarkable surgical practice of John Benjamin Murphy. Urbana: University of Illinois Press. ISBN 0-252-01958-X. 
2. ^ Musana KA, Yale SH (August 2005). "Murphy's Sign". Clin Med Res 3 (3): 132. PMC 1237152. PMID 16160065. http://www.clinmedres.org/cgi/pmidlookup?view=long&pmid=16160065. 
3. ^ Musana K, Yale SH (May 2005). "John Benjamin Murphy (1857 - 1916)". Clin Med Res 3 (2): 110–2. PMC 1183442. PMID 16012130. http://www.clinmedres.org/cgi/pmidlookup?view=long&pmid=16012130.