Kidney stones are common. Some types run in families. They often occur in premature infants.
There are different types of kidney stones. The cause of the problem depends on the type of stone.
Stones can form when urine contains too many substances that can form crystals. These crystals can develop into stones over weeks or months.
Calcium stones are most common. They are most likely to occur in men ages 20 to 30. Calcium can combine with other substances to form the stone.
Oxalate is the most common form of calcium stone. Oxalate is present in certain foods such as spinach. It's also found in vitamin C supplements. Diseases of the small intestine increase your risk of these stones.
Calcium stones can also form from combining with phosphate or carbonate.
Other types of stones include:
Cystine stones can form in people who have cystinuria. This disorder runs in families. It affects both men and women.
Struvite stones are mostly found in women who have a urinary tract infection. These stones can grow very large and can block the kidney, ureter, or bladder.
Uric acid stones are more common in men than in women. They can occur with gout or chemotherapy.
Other substances such as certain medicines also can form stones.
The biggest risk factor for kidney stones is not drinking enough fluids. Kidney stones are more likely to occur if you make less than 1 liter of urine a day.
You may not have symptoms until the stones move down the ureters. These are the tubes that carry urine into your bladder. When this happens, the stones can block the flow of urine out of the kidneys.
The main symptom is severe pain. It starts suddenly and may go away suddenly:
Pain may be felt in the belly area or side of the back.
The stone is blocking urine flow and causing an infection or kidney damage.
The pain cannot be controlled.
Today, most treatments are much less invasive than in the past.
Lithotripsy is used to remove stones slightly smaller than a half an inch that are located in the kidney or ureter. It uses sound or shock waves to break up stones. Then, the stone fragments leave the body in the urine. It is also called extracorporeal shock-wave lithotripsy or ESWL.
Procedures performed by passing a special instrument through a small surgical cut in your skin and into your kidney or ureters are used for large stones in or near the kidney. These procedures may also be used when the kidneys or areas around them are not formed correctly. The stone is removed with a tube (endoscope).
Ureteroscopy may be used for stones in the lower urinary tract. This procedure avoids a surgical cut. A long, thin telescope is placed through the bladder opening and into the ureter to break up or remove your stone.
Rarely, open surgery (nephrolithotomy) may be needed if other methods do not work or are not possible.