Kidney pain, or renal pain, is usually centered in the lower back, just below the rib cage. The pain may spread to the sides, the abdomen or down into the groin. In men, it may even radiate into the testicles. The pain may be constant and feel like a dull ache, or it can be sharp and intermittent. Occasionally it may be accompanied by hematuria (blood in the urine). Diagnosing renal pain can be difficult: a number of possible disorders can cause similar symptoms.
Urinary Tract and Kidney Anatomy
Your kidneys are twin, red brown organs roughly the size of your fist. They are located on either side of the spine, just below the lower ribs. They are part of the urinary tract, filtering impurities, excess fluids and waste products out of the blood, and excreting them as urine.
To better understand the diseases discussed on this site, here are some definitions of words commonly related to the urinary tract or kidney anatomy:
Nephrons: Nephrons are millions of tiny tubes in the kidneys responsible for filtering wastes and excess fluid from the body.
Ureter: The ureters are long, thin tubes that transport urine from the kidneys to the bladder.
Bladder: The bladder stores urine until it is full, then excretes it through the urethra and out of the body.
Urethra: The urethra is the exit point for the urinary tract. It is a tube that voids urine from the bladder.
Causes of Renal Pain
A number of disorders can cause renal pain. Note, however, that many renal disorders present without any noticeable symptoms. Disorders that do cause discomfort include:
Other Causes of Flank Pain
Many other conditions cause discomfort, back spasms and other symptoms that mimic renal disorders. Lower back injury is a common complaint. Other conditions include:
appendicitis: Appendicitis is an inflammation of the appendix.
ectopic pregnancy: An ectopic pregnancy occurs when a fertilized ovum develops outside of the uterus. An ectopic pregnancy can occur in the fallopian tubes, or even in the abdominal cavity.
gallstones: Gallstones are calculi, or mineral buildups, that occur in the gallbladder.
hepatitis: Hepatitis is an inflammation of the liver. Infections and alcohol abuse are among the main causes of hepatitis.
stomach ulcers: Stomach ulcers occur when gastric juices eat into the stomach or duodenum.