Kinds of kidney stones

The common groups include calcium stones, uric acid stones, struvite stones and cystine stones. Calcium stones form from minerals in urine. Uric acid stones are linked with concentrated, acidic urine. Struvite stones can develop alongside certain urinary infections and may grow quickly. Cystine stones result from a rare inherited condition that changes how the kidneys handle an amino acid. A passed stone can sometimes be collected and analysed; urine and blood tests may add useful context. An abdominal ultrasound can look for stones or urinary blockage without using radiation.

The stone’s composition is only part of the picture. Dehydration, diet, medicines, family history, urinary infection and other health conditions can affect risk. A stone may cause flank pain, abdominal pain, painful urination or difficulty passing urine, although symptoms vary with its position and movement.

Arrange a GP Consultation if you have recurring stone symptoms, a history of stones or questions about prevention. Keep any stone you pass if a clinician advises this, because laboratory analysis can help distinguish its type. Drink fluids regularly unless you have been told to restrict them, and follow personalised advice about salt, animal protein or other dietary factors. Do not start supplements or make a highly restrictive diet change without professional guidance.

Seek urgent medical care for severe or worsening flank or abdominal pain, fever or chills with urinary symptoms, repeated vomiting, visible blood in urine, or difficulty passing urine. These features can signal blockage or infection, which needs prompt assessment. Contact a clinician soon for persistent pain, recurring urinary symptoms or a stone that does not pass.

Ask which stone type is most likely, whether a passed stone should be analysed, which tests are appropriate, how much fluid is suitable for you, and whether any medicine or dietary change could reduce recurrence.