Kidney stones are masses of various particles that are sometimes formed in the kidneys. When these kidney stones move into the ureters, the tubes connecting the kidneys to the bladder, a blockage may occur that prevents urine from passing out of the body in a normal fashion. The majority of kidney stones contain calcium, but there are other types of kidney stones as well, such as those made as a result of too much acid in the kidneys.
Among the most common types of kidney stones are those that contain calcium. These calcium stones tend to also contain either oxalate or phosphate, both substances being produced naturally by the human body. The bones and muscles of the body need calcium in order to function properly. The calcium that is not used by the body is processed by the kidneys and passed out of the body through the urine. If calcium remains in one of the kidneys and combines with other waste materials, a kidney stone may form.
Struvite stones are another of the more common types of kidney stones. A struvite stone is sometimes referred to as an infection stone because this type of stone tends to develop after a urinary tract infection. Struvite stones contain a type of mineral known as magnesium and produce ammonia as a waste product.
Another of the more common types of kidney stones are uric acid stones. This type of stone may develop when there is too much acid in the urine and is more common in patients who have diminished kidney function. If uric acid stones become a common occurrence, the patient may be advised to reduce consumption of certain foods, especially meat.
It is possible for a patient to have multiple types of kidney stones, particularly if there is impaired kidney function. Blood tests can sometimes suggest the type of kidney stone present. However, some doctors prefer to examine the stone itself to be certain of the type.
Regardless of which one of the types of kidney stones found in an individual patient, research has shown that if the patient has had more than one kidney stone, the development of future kidney stones is likely. If chronic kidney stones become a chronic condition, further testing may be ordered to make sure there is no serious medical issue that should be addressed. Certain diseases, such as a progressive kidney disease known as polycystic kidney disease, is known to cause repeated instances of kidney stones in many patients.