Kidney stones are usually formed following a build-up of certain chemicals in the body.
This build-up may be any of the following:
- uric acid – a waste product produced when the body breaks down food to use as energy
- cysteine – an amino acid that helps to build protein
Certain medical conditions can lead to an unusually high level of these substances in your urine.
You’re also more likely to develop kidney stones if you don’t drink enough fluids.
Recurrent kidney stones
Some people are particularly likely to keep on developing kidney stones, including people who:
- eat a high-protein, low-fibre diet
- are inactive or bed-bound
- have a family history of kidney stones
- have had several kidney or urinary infections
- have had a kidney stone before, particularly if it was before you were 25
- have only one fully working kidney
- have had an intestinal bypass (surgery on your digestive system), or a condition affecting the small intestine, such as Crohn’s disease