Kidney stones are formed because of an excess of certain chemicals. Excess of chemicals are usually flushed out through the urine. When they are not flushed out, they crystallize and get deposited in different places in the urinary tract. The urinary tract includes kidneys, bladder, ureters and urethra. Stones formed in the urinary tract cause severe pain when they block the passage of urine. If kidney stones do not block passage of urine then they may be passed through urine spontaneously or through certain non surgical methods. Passage of stones depends on their size, composition and location.
Kidney stones vary in size depending on the amount of chemical compounds deposited. Size of a kidney stone can range anywhere from less than a millimeter to about an inch or more. Small stones usually do not show any symptoms unless caused by an infection. Kidney stones about the size of 4-5 millimeter can pass through urine spontaneously. Whereas, stones the size of 6 mm and more cause severe pain and cannot pass through urine.
Calcium stones are quite common and easy to pass through urine. Struvite stones are caused by urinary infection. This type tends to be large because of its composition.
Stones formed in the kidney have to move through a narrow ureter to be excreted in the urine. If they are located near the ureter and are of a small size, kidney stones can be passed easily. Stones far off from the opening can take a longer time to get to the ureter. This time gives space for more chemicals to accumulate and the stone to grow bigger in size.
Small stones can be passed easily by drinking lots of water and by making a few changes in your diet. Some large stones can be broken into smaller pieces by non surgical methods and then passed through urine.