Kidney or Flank Pain

Abdomen | Nephrology | Kidney or Flank Pain (Symptom)


Kidney pain is caused by infection, inflammation, injury or enlargement of the kidney, or by conditions that block the flow of urine out of the kidney.


Pyelonephritis (kidney infection) and kidney stones are the most common causes of kidney pain. Pyelonephritis is often accompanied by other symptoms of urinary tract infection, such as burning with urination, frequent or urgent need to urinate, bloody urine, fever, and nausea with or without vomiting. Kidney stones may also cause bloody urine, fever, and nausea with or without vomiting. However, the pain tends to come and go in waves.

Stretching of the capsule around the kidney can cause pain, but many of the conditions that cause kidney enlargement develop gradually without much pain. These conditions include kidney cancer or benign tumours, polycystic kidney disease, and hydronephrosis (enlargement of the ureters, the tubes that drain the bladder).

Bleeding in the kidney can cause more rapid enlargement, but this may be easier to diagnose since it is often associated with trauma. Kidney damage due to a blocked artery is a rare cause of kidney pain, as is poststreptococcal glomerulonephritis, an uncommon complication of streptococcal infections, such as strep throat (bacterial throat infection) and impetigo.

Kidney pain may accompany other symptoms affecting the urinary tract including: bloody or pink-colored urine (hematuria), cloudy urine, difficult or painful urination, or burning with urination (dysuria), foul-smelling urine, frequent urination, urgent need to urinate, urination at night (nocturia).