What are possible causes of kidney pain?
Because the kidneys filter the blood, form urine, and pass it out of the body through tubes called ureters, problems in any of these areas could result in pain. Some of the more common causes of kidney pain include:
- Kidney stones: Kidney stones form from the buildup of minerals or chemical wastes inside the body. Stones may be as small as a grain of sand or larger than a pearl. If they are small they may pass out of the body. However, larger stones may get stuck in the urinary tract and prevent urine from passing. In either case, intense pain can result.
- Urinary tract infection: An infection anywhere along the urinary tract caused by bacteria left behind after urination. Symptoms may include fever, painful urination, cloudy urine, and general fatigue.
- Kidney infection (pyelonephritis): A kidney infection occurs when bacteria from a bladder infection has spread to the kidneys. People with diabetes or who have a blockage in the urinary tract are more likely to get a kidney infection. In chronic cases, some problem in the urinary tract causes urine to flow backwards from the bladder up to the kidneys, resulting in repeated infections and possibly permanent kidney damage.
- Polycystic kidney disease: An inherited condition in which fluid-filled sacs (cysts) develop inside the kidneys. As the cysts expand, the kidneys become enlarged and may eventually lose their ability to function.
- Injury or trauma: Any strong impact or blunt force to the kidney area (such as in contact sports or an accident) may cause a laceration or other physical damage to the kidneys. Such incidents may also cause a disruption of normal blood flow to the kidneys. Acute (sudden) kidney failure may result from kidney trauma.
- Kidney (renal) cancer: Renal cell carcinoma is the most common type of kidney cancer. It usually affects people in their 60s or 70s, rarely appearing in those under the age of 50. If they occur at all, symptoms include blood in the urine, a persistent pain in the back or side just below the ribs, and a lump or swelling in the side.