What are kidney stones?
Kidney stones are hard, crystalline mineral deposits that form within the kidneys. They occur when there is an imbalance between the amount of minerals that are filtered through the kidneys (e.g. calcium, oxalate, uric acid) and the amount of fluid going through the kidneys (ie: water). If there is a high mineral content going through the kidneys but only a small amount of water then the minerals may precipitate out and form kidney stones. The urine may also lack substances that prevent the formation of kidney stones, such as citrate.
There are several different types of kidney stones including calcium stones (calcium oxalate, calcium phosphate), uric acid stones, struvite (infection) stones and cysteine stones.
Presentation
Kidney stone pain is often described as “the worst type of pain”. Typically the pain occurs in the flank area (loin) with radiation down into the groin. The pain is often difficult to control with simple analgesics, and is not made better with lying still, moving around or applying simple hot packs. The pain is often associated with nausea and vomiting, and blood in the urine (haematuria) may also be present. Fevers, rigors (shakes) or dysuria (burning sensation when passing urine) may suggest the presence of an infection, and so immediate medical advice should be sought.