Kidney stones occur in about 5 percent of Americans, according to the National Kidney and Urologic Diseases Information Clearinghouse. The stones are composed of collections of tiny crystals, and it is not always known what causes them. Some known causes include urinary tract infections, and kidney and metabolic disorders. Generally, there are no problems caused by kidney stones, but they can potentially cause pain, urinary problems, infections or kidney failure.
Pain
Generally, pain is the first problem noticed by somebody with a kidney stone. It can be a cramping, sharp pain in the back, side or lower abdomen, and may radiate to the groin. If the kidney stone does not pass through the urinary tract, it may cause continuous pain. If the pain is accompanied by decreased urinary output, this can be a sign of urinary problems caused by the stone.
Urinary Problems
Some stones are small enough that they will pass through the urinary tract without causing any problems. If a stone is large enough, however, it can block the flow of urine and even cause kidney damage. The damage is typically reversible, but the stone may need to be removed surgically if it does not pass on its own.
Infections
Obstruction of the flow of urine predisposes the urinary tract to infections. Fever, chills and burning with urination are signs of infection accompanying the presence of a kidney stone. Infections may occur in the bladder, called cystitis, or kidneys, called pyelonephritis. If this occurs, the usual treatment of hydration and pain medicines will need to include antibiotics.
Kidney Failure
If left untreated, kidney stones can slowly build up over time and gradually restrict the flow of urine out of the kidney, leading to kidney disease or failure over time. The urine backs up into the small tubes in the kidneys and damages the cells. Another possible mechanism for kidney damage from stones are rough, ridged or serrated edges of the stones abrading the tissues in the kidney.
References
- National Kidney and Urologic Diseases Information Clearinghouse: Kidney Stones in Adults
- "Harrison's Principles of Internal Medicine"; Anthony S. Fauci; 2008
