The Kidney Punch Test: What Is It and How Is It Done?

The kidney punch test, also known as Murphy’s kidney punch or Costovertebral Angle Tenderness Exam (CVA Tenderness Exam), is a clinical test done to assess the kidneys as well as its surrounding areas.

This is usually done during a physical examination, especially if the patient is experiencing symptoms such as pain in the flank, groin and or abdomen, vomiting, burning sensation when urinating, fever, and chills. When a patient is experiencing more than one of these symptoms, the health professional will conduct a kidney punch test. 

A positive result from the kidney punch test might indicate the possibility of kidney disease. The patient will have to undergo further tests to confirm if they do have a disease and what could be causing the pain.

The kidney punch test involves striking the costovertebral angle. The costovertebral angle is the acute angle located at the bottom of the ribcage and the spine. To locate the costovertebral angle, count to the 12th rib of the patient’s ribcage and locate the center where the spine and the rib meet.

When this angle is hit by blunt force, a patient with some form of kidney disease such as pyelonephritis, will feel pain. The pain is due to the inflammation of the kidney. Since the kidney is directly anterior to the costovertebral angle, disturbance in the inflamed tissues elicits pain.

Steps in Conducting a Kidney Punch Test

1. The examiner will assist the patient into a sitting position and make sure that they are sitting as comfortably as possible.
2. The examiner should position themselves at the patient’s back. 
3. The goal is to find the costovertebral angle by locating the 12th rib. Below the 12th rib is an acute angle between the spine. This angle is the costovertebral angle. 
4. Then, the examiner will lay the non-dominant hand flat on this area.
5. The examiner will then make a fist with their dominant hand. 
6. Using the dominant hand, the examiner will gently but firmly punch or thump the back of their non-dominant hand.
7. Then the examiner will ask patient if they felt any discomfort or pain.

Note: A forceful blow will cause pain even in normal patients. The examiner must be gentle in applying force to the costovertebral angle. 

If the patient reports pain during the kidney punch test, they have tested positive for the test and this might indicate that there is inflammation in the kidneys. 

If the person tests positive in the kidney punch test, they most likely have inflammation in the kidneys or the area around the kidneys.

Diseases that might be attributed to a “positive” kidney punch include:

• Kidney Infection (pyelonephritis) – An infection caused by bacteria that generally multiply starting in the bladder and then travels to one or both of the kidneys. 
• Kidney Stones – Kidneys filter waste from your blood released as urine. When the body does not have enough fluid, waste in the kidney sticks together and builds up forming kidney stones. 
• Urinary Tract Infection – Infection causing inflammation in any part of the urinary tract which includes the bladder, kidney, ureters and urethra.
• Ureteral Obstruction – Caused by a blockage in the ureters. The ureters are the tubes that transport urine from the kidney to the bladder. Blockage can be Tumors, swelling, ureteral stones or any abnormalities can cause this blockage.

Other Diseases that Can Be Linked to CVA Tenderness

• Pelvic Inflammatory Disease – infection in any part of the female reproductive organs which includes the uterus, ovaries, and fallopian tubes. 
• Abdominal Abscess – A collection of pus or infected fluid in the belly (abdominal cavity). This infection happens near the kidneys and other organs such as the liver and pancreas.

The kidney punch test alone cannot fully confirm diagnosis. It is only an indication that there can be inflammation in the urinary tract and the areas that surround it. Further tests such as stool, blood and urine exam must be conducted.

Learn more about Kidney Disease here.