Kidney stones refer to a condition characterized by the formation of stones in the kidneys, with diagnostic and therapeutic implications that vary depending on the type of stone involved. There are four main types: calcium oxalate stones, which are the most common; calcium phosphate stones; uric acid stones, linked to purine metabolism; and struvite or cystine stones, which are rarer and often associated with chronic urinary tract infection or a genetic disorder, respectively. For an overview focused on the general formation of stones and their prevention through hydration, the page dedicated to urinary stones usefully complements this breakdown by type.
Calcium oxalate stones account for the majority of kidney stones. Their formation is promoted by a diet high in oxalates, insufficient hydration, and certain nutritional deficiencies: Vitamin B6 plays a role in oxalate metabolism, and an appropriate intake is sometimes recommended as part of the management of certain cases of hyperoxaluria—always under medical supervision and following a detailed laboratory evaluation. Magnesium is also one of the natural protective factors against calcium crystallization.
Uric acid stones form when urine is abnormally acidic and high in uric acid, often in a metabolic context similar to that of gout, as both conditions share the same underlying cause of hyperuricemia. Treatment combines medically prescribed urine alkalization with targeted lifestyle and dietary measures (notably reducing excessive intake of red meat and alcohol).
The diagnosis relies on imaging; a non-contrast abdominal CT scan is the gold standard for precisely locating the stone(s) and assessing their size. Analysis of the passed or extracted stone, when possible, helps determine its exact composition and guide prevention in a targeted rather than a generic manner. Blood and urine tests complete this evaluation to identify any underlying metabolic factors, including magnesium deficiency.
Treatment depends on the size and location of the stone. Small stones can be passed naturally with increased fluid intake and appropriate pain management. For stones larger than a certain size, the urologist may recommend extracorporeal shock wave lithotripsy, ureteroscopy, or, more rarely, surgery. For uric acid stones, cherry stems are traditionally used as a complementary diuretic, though they are not a substitute for prescribed medical treatment.
The risk of kidney stone recurrence is high—approximately 50% over ten years, according to urological data—which justifies regular nephrological or urological follow-up after an initial episode. This follow-up relies on maintaining adequate daily hydration tailored to the type of stone identified, combined with periodic laboratory tests to adjust preventive measures over time.
