How are kidney stones formed?

A brief overview of the anatomy of the urinary tract would help to explain how kidney stones develop. The urinary tract is composed of two kidneys and ureters, a bladder and a urethra. Urine is produced by the kidneys, which are located towards the middle of the back, below the ribs. The kidneys remove waste products and excess fluid from the blood and convert this to urine. The urine passes out of the kidney through small tubules into the hollow portion of the kidney (renal pelvis) and then into the ureter, a narrow tube connecting the kidney to the bladder. The urine collects in the bladder until it passes out of the body through the urethra. The process by which the stone formation occurs is super-saturation of urine.

Here is simple example illustration the formation of the stone. Imagine a glass of water containing little salt. If you add some more salt, it dissolves .When you add more and more salt, a stage is reached when the water is no longer able to dissolve the salt added to it. This is because the solution is supersaturated with the salt. Above this point, any little amount of salt added to the solution will start precipitating. This is exactly the mechanism by which kidney stones from except that the solution is urine and the chemical composition of salt is different. kidney stones are nothing but small, solid crystals that develop when salts or minerals in urine become solid . "Once a kindey stone from, the probability that a second stone will from within five to seven years is approximately 50%, inside the kidneys or uterus. The solid masses may be too small as a grain of sand or as large as a lemon. Tiny crystals leave the body while urinating without any pain or harm. However, they can build up inside the kidney. These large kidney stones when move out of the kidney and progress through the tubes that carry urine from kidney to bladdeer may cause server pain.

While passing if it gets stuck to ureter; it will cause infections that will lead to permanent kidney damage. They may be smooth, staghorn or jagged to make the situation even worst or better.

Kidney Stones can be formed practically any where in the urinary system, like kidney, ureter, and bladder. Depending on where they are located, kidney stones are known as urinary calculi, urinary tract stone disease, renal calculi, nephrolithiasis, ureterolithiasis and urolithiasis.

The most common type of kidney stone contains calcium in combination with either oxalate or phosphate. Other chemical compounds that can form stones in the urinary tract include uric acid and the amino acids cystine.

A study done in the tribal population of India showed that fluoride in vivo may behave as a mild promoter of urinary stone formation by the excretion of insoluble calcium fluoride, increasing the oxalate excretion and mildly increasing the oxidative burden.

Kidney stones form when there is a decrease in urine volume and/or an excess of stone-forming substances in the urine. Dehydration from reduced fluid intake or strenuous exercise without adequate fluid replacement increases the risk of kidney stones.

Obstruction to the flow of urine can also lead to stone formation. Kidney stones can also result from infection in the urinary tract; these are known as struvite or infection stones. These large kidney stones when move out of the kidney and progress through the tubes that carry urine from Kidney to bladder may cause severe pain.