Kidney pain arises from infection of or injury to the kidneys.

If your back or flank hurts, you might understandably think you have kidney pain. But more often than not, your kidneys are probably not involved. Many people are surprised to learn that their kidneys are located relatively high on the back, just under the lower ribs (retroperitoneal space).

How do you know if what you're calling kidney pain actually is kidney pain? There's no sure way, but the likelihood that it is directly related to your kidneys increases with the presence of other signs and symptoms and with test results.

Pain in the upper back that is a dull, one-sided ache, particularly if it is accompanied by fever and urinary symptoms may be real kidney pain. This may due to a kidney infection (pyelonephritis).

Kidney stones do cause pain, but it's not kidney pain. While stones are usually painless as long as they remain in the kidney, it is their movement out of the kidney that really hurts. When a kidney stone begins to travel through the ureter on its way to your bladder, it typically causes waves of sharp, intense pain, which doctors call renal colic or ureteral colic.

Call your doctor for a same-day appointment if you have:

  • Constant, dull, one-sided pain in your back or flank
  • Fever, body aches and fatigue
  • Recent history of a urinary tract infection

A blood clot or a hemorrhage in your kidney causes sudden pain in your lower abdomen and flank, and possibly a great deal of blood in your urine. This is an uncommon complication of a kidney injury or other kidney disorders, including atherosclerosis of the renal artery, a bleeding disorder or kidney embolism. Any interruption in circulation to the kidney is an emergency, so it's important to seek emergency care if you develop severe kidney pain, with or without bloody urine.

May 20, 2011