A kidney stone are what the name implies: a hard piece of material, stone-like, that sometimes forms in the kidney. The kidneys are where urine is produced, and when certain substances in urine are present at too-high levels, a stone may form.
Problems can occur when kidney stones leave the kidneys and pass into the urinary tract. Sometimes they pass from the body on their own without problem. But if one gets lodged somewhere in the urinary tract, it can cause bleeding and extreme pain. About one in 10 people will get a kidney stone at some point in their lives.
Causes of Kidney Stones
Urine is made up a variety of components, including calcium, oxalate and phosphorus. These are normal substances that are often in present in urine, but in some cases, the levels become higher than normal. This may be the result of a urinary tract infection, a medical condition that affects the levels of these substances or digestive problems. Whatever the cause, these substances can accumulate and solidify in the kidneys until a stone has formed.
Sometimes kidney stones cause no problems. But if you experience pain while urinating or have blood in the urine, then you might have a kidney stone. Other symptoms include lower back or abdominal pain, or pain that's accompanied by nausea and vomiting. People with these symptoms should see a doctor to determine if a kidney stone is the cause.
How a kidney stone is treated will depend on its size and the symptoms you are experiencing. For a small kidney stone that is not obstructing the urinary tract, you may be given pain medication and encouraged to drink lots of fluids to pass the kidney stone. For larger stones that are obstructing the urinary tract and causing major symptoms, several methods can be used to remove the stone. They include crushing the stone using a shock wave machine (shock wave lithotripsy), breaking or removing the stone with a uteroscope (uteroscopy) and removing the stone from the kidney with a nephroscope (percutaneous nephrolithotomy).
SOURCES: U.S. National Institute of Diabetes and Digestive and Kidney Diseases; National Kidney Foundation