Stones form inside the kidney due to minerals crystallizing and precipitating into tiny particles in the urine while in the kidney.
Kidney / Urinary Stones
Stones form inside the kidney due to minerals crystallizing and precipitating into tiny particles in the urine while in the kidney. Once formed, the tiny particles enlarge to form stones. Stones can range in size and get up to several centimeters in size or can fill the entire kidney with a stone called a staghorn calculus, although this is rare. Stones are usually made of calcium, oxalate and/or phosphate but can be made of other substances such as uric acid. The number of people in the United States with kidney stones has been increasing over the past 20 years. Caucasians are more prone to develop kidney stones than African Americans. Although stones occur more frequently in men, the number of women who get them has been increasing. Kidney stones strike most typically between the ages of 20 and 40. If a person forms a stone, there is a 50 percent chance they will develop another stone. Having a first degree relative with a stone may increase the risk of stone formation. Certain foods may promote stones in susceptible people. Climate and water intake may also play a role in stone formation.
Other risk factors include obstruction to urinary passage like in prostate enlargement or stricture disease, hyperparathyroidism, or certain kidney diseases that affect how certain minerals are excreted in the urine. Certain medications, such as calcium pills, certain diuretics or antacids can also contribute to the formation of stones.
Smaller stones can pass into the ureter and often get stuck there. When that happens, the kidney, which is producing urine, swells because the urine has nowhere to go so it backs up in the kidney. The swelling stretches the capsule of the kidney, which causes pain. The pain can be severe. Most stones that enter the ureter will pass into the bladder and be voided out. Stones in the kidney are usually not painful, and many people who harbor them are not aware of it. They may never pass. Kidney stones can become infected or can enlarge to the point where they can cause the kidney to malfunction.
Treatment of kidney stones is usually surgical, but it must be emphasized that most stones will pass without the need for surgery. On occasion stones can respond to medical dissolution. Surgery is indicated when:
Severe pain that fails to resolve
Infection in the kidney above the stone
Sudden deterioration of kidney function
Stones that are growing on x-ray appearance
Kidney Stone Prevention
Once someone develops a kidney stone they have a 50% chance of developing another one within their lifetime. The more stones someone develops, the greater the chance of a recurrence. For this reason, prevention becomes paramount. In most cases, a metabolic abnormality can be detected and used to put together a comprehensive program for stone prevention. In order to do so, we generally need a 24 hour collection of urine, a blood test and the kidney stone.
There is only one universal recommendation for stone formers and that is to increase water intake. Insufficient water intake is the most common cause of stone formation.
Its important to know that everyone’s kidney stone is unique, so what works for one person may not work for another or can even may make things worse. That is why we encourage everyone to undergo a comprehensive evaluation. Some treatments are also counterintuitive, for example someone who forms calcium stones may be advised to reduce calcium intake and others may be advised to actually increase calcium intake. Treatment modalities include full dietary analysis and advice, as sometimes there are medications that can be used for prevention and sometimes there are medications that need to be changed in order to reduce stone risk.