There are many causes of flank pain. Flank pain is pain that manifests on the side of the trunk, between the abdomen and the back. It may indicate a problem with the kidneys, especially if the flank pain is accompanied by fever, chills, bloody urine and a persistent urgency to urinate. Other causes of flank pain can produce symptoms as well.
Pyelonephritis
Pyelonephritis can cause flank pain. According to the National Institute of Diabetes and Digestive and Kidney Diseases, pyelonephritis, also known as a kidney infection, is often caused by bacteria that spread from the bladder. There are many possible causes of kidney infection including bladder infections, use of catheters to help empty the bladder, use of a cystoscope for evaluating bladder and urethra health, urinary tract surgery, certain medical conditions and anatomical abnormalities in the urinary tract that obstruct the flow of urine.
Common signs and symptoms associated with pyelonephritis include back, flank and groin pain, frequent urination, burning on urination, fever, nausea and vomiting and bloody urine. The NIDDK states that some kidney infections can lead to serious health complications such as irreversible kidney damage and chronic kidney disease.
Polycystic Kidney Disease
Polycystic kidney disease can cause flank pain. MayoClinic.com states that polycystic kidney disease is a condition in which groups of cysts--fluid-filled sacs--form within the kidneys. The disease that causes cysts to develop within the kidney can also cause cysts to develop in other parts of the body, although the kidneys are often the most severely affected structure.
According to MayoClinic.com, the most significant problem for a person with polycystic kidney disease is hypertension or elevated blood pressure. Another injurious complication of polycystic kidney disease is kidney failure. Common signs and symptoms associated with polycystic kidney disease include back and flank pain, headache, expansion of the abdomen, bloody urine, frequent urination, kidney stones, kidney failure and urinary tract infections. Polycystic kidney disease varies in severity from person to person.
Kidney Stones
Renal calculi can cause flank pain. According to the University of Maryland Medical Center, renal calculi, also known as kidney stones, are solid masses composed of tiny crystals that separate from the urine. One or more stones may be in various parts of the urinary tract simultaneously, such as the kidneys and ureters. The UMMC states that the most common cause of renal calculi is dehydration.
Kidney stones may not cause symptoms until they begin traveling down the ureters. If the stones block the flow of urine through the ureter, the affected-side kidney can swell, causing severe pain in the back and flank. Kidney stones tend to occur in men between the ages of 20 and 30, although women can be affected too. If a person has had kidney stone problems before, he is more likely to experience kidney stone-related pain in the future. According to the UMMC, certain types of kidney stones appear to run in families.
