Flank pain

Alternative names
Pain - side; Side pain

Flank pain refers to pain in the side of the trunk between the right or left upper abdomen and the back.


Flank pain often means kidney trouble. If flank pain is accompanied by fever, chills, or urinary problems, then a kidney is the likely source.

One in seven people in the US has kidney stones at some time. The pain from a kidney stone is agonizing, comes in sharp stabbing waves or spasms, and usually radiates into the groin.

Common Causes

  • Kidney problems       o Acute pyelonephritis (kidney infection)       o Kidney stone       o Kidney abscess  
  • Shingles (flank pain with one-sided rash)  
  • Spinal arthritis  
  • Disk disease  
  • Muscle spasm

Home Care

Treatment depends on the cause. Follow your health care provider’s instructions.

Rest, physical therapy, and exercise may be recommended for flank pain caused by muscle spasm.

Anti-inflammatory drugs and physical therapy may be prescribed for flank pain caused by spinal arthritis. Continue physical therapy exercises at home.

Antibiotics are used to treat most cases of pyelonephritis. Plenty of fluids and pain medications are used to treat kidney stones. Sometimes hospitalization is required for either of these conditions.

Call your health care provider if

  • There is flank pain accompanied by high fever, chills, nausea, or vomiting.  
  • There is blood (red or brown color) in the urine.  
  • There is prolonged, unexplained flank pain.

What to expect at your health care provider’s office

If the pain is related to an injury, the condition will first be stabilized. Then the health care provider will obtain your medical history and will perform a physical examination.

Medical history questions documenting flank pain in detail may include the following:

  • Location       o Is the pain on one side only (unilateral) or both sides?       o Which side?  
  • Quality       o Is the pain mild?       o Is the pain periodic and changing intensity over minutes?       o Is the pain crampy/colicky?       o Is the pain severe enough to require narcotic pain relievers?  
  • Time pattern       o Did the pain begin recently?       o Has the pain been gradually getting worse over months?       o Did the pain rapidly get worse?  
  • Radiation       o Does the pain go into your groin?       o Does the pain go into your back?       o Does the pain go up into your chest?  
  • Associated complaints       o Does the pain occur with nausea or vomiting?       o What other symptoms are also present?

Fluid intake and output may be monitored and recorded.

DIAGNOSTIC TESTS that may be performed include the following:

  • Urinalysis and urine culture  
  • Renal or abdominal ultrasound  
  • Abdominal CT scan  
  • Cytoscopy  
  • Intravenous pyelography  
  • Retrograde ureteropyelography  
  • Serial urine and serum analysis  
  • Voiding cystourethrography  
  • Lumbosacral spine X-ray


Johns Hopkins patient information

Last revised: December 8, 2012
by Brenda A. Kuper, M.D.

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All ArmMed Media material is provided for information only and is neither advice nor a substitute for proper medical care. Consult a qualified healthcare professional who understands your particular history for individual concerns.