What are kidney stones?
Kidney stones are solid accretions (crystals) of dissolved minerals in urine found inside the kidneys or ureters. Also known as nephrolithiasis, urolithiasis or renal calculi. They vary in size from as small as a grain of sand to as large as a golf ball. Kidney stones typically leave the body in the urine stream; if they grow relatively large before passing, their jagged crystalline shape can cause severe pain in the ureters and urethra.
Consumption of too much calcium can aggravate the development of kidney stones, since the most common type of stone is calcium oxalate. The calcium renders these stones radio-opaque and they can be detected by an KUB (an X-ray of the abdomen that extends from the kidneys to the bladder).
Other examples of kidney stones include struvite (magnesium, ammonium and phosphate), uric acid, calcium phosphate, or cystine (the amino acid found only in people suffering from cystinuria). There are many types of kidney stone, and a person may be susceptible to only some of them.
Kidney stones (renal calculi or nephrolithiasis) are made of salts, minerals, and other substances normally found in the urine that stick together and build up on the inner surfaces of the urinary system. Stones can develop in the kidney, the ureter, or the bladder. About 80% of kidney stones contain calcium compounds, mostly calcium oxalate, and are called calcium stones.
Kidney stones (calculi) are hardened mineral deposits that form in the kidney. They originate as microscopic particles and develop into stones over time. The medical term for this condition is nephrolithiasis, or renal stone disease. The kidneys filter waste products from the blood and add them to the urine that the kidneys produce. When waste materials in the urine do not dissolve completely, crystals and kidney stones are likely to form.
Small stones can cause some discomfort as they pass out of the body. Regardless of size, stones may pass out of the kidney, become lodged in the tube that carries urine from the kidney to the bladder (ureter), and cause severe pain that begins in the lower back and radiates to the side or groin. A lodged stone can block the flow of urine, causing pressure to build in the affected ureter and kidney. Increased pressure results in stretching and spasm, which cause severe pain.
More information on kidney stones
What are kidney stones? - Kidney stones are solid accretions (crystals) of dissolved minerals in urine found inside the kidneys or ureters. Also known as nephrolithiasis, urolithiasis or renal calculi.
What are kidney stones made of? - Kidney stones consist of a center that consists of crystal-like substances, and a surrounding region that is composed of layers. Kidney stones are composed of different chemical substances.
What are the symptoms of kidney stones? - Symptoms often occur when a stone migrates into the ureter, the tube that carries urine from the kidney to the bladder, and prevents the drainage of urine from the kidney.
What causes kidney stones? - The development of the stones is related to decreased urine volume or increased excretion of stone-forming components such as calcium, oxalate, urate, cystine, xanthine, and phosphate.
What are the risk factors for kidney stones? - Kidney stones affect about 12% of men and 5% of women by the time they are 70 years old. Kidney stones that strike women are more apt to occur during pregnancy.
How are kidney stones diagnosed? - Diagnosis of renal stone disease involves a medical history, physical examination, laboratory evaluation, and imaging tests.
What're treatment options for kidney stones? - Treatments of kidney stones include dietary modifications (including the advice to drink plenty of water), medications, and use of a lithotriptor.
What drug treatments are available for treatment and prevention of kidney stones? - Diuretics are commonly used in the treatment of high blood pressure and other disorders to eliminate fluid and sodium from the body. Citrate salts are often given to people with calcium oxalate or uric acid stones.
What dietary factors and lifestyle measures are used for prevention of kidney stones? - The most important recommendations for reducing the risk for calcium stones are increasing fluid intake, restricting sodium, and reducing protein intake.