Urinary stones, also known as kidney stones or urolithiasis, are crystalline deposits that form in the urinary tract when certain substances (calcium, oxalate, uric acid, or cystine, depending on the case) exceed their solubility threshold in urine. According to the French Society of Urology, calcium oxalate accounts for 70 to 80% of stones, followed by calcium phosphate, uric acid, struvite (stones of infectious origin), and, more rarely, cystine (genetic origin). For a comprehensive overview of the condition and its various types, the page dedicated to kidney stones usefully complements this approach, which focuses on the formation of the stones themselves.
A small stone may pass without causing any noticeable symptoms. However, when it partially obstructs the ureter, it triggers renal colic: a sudden and intense pain in the lower back that radiates toward the groin, often accompanied by nausea, frequent urination, or blood in the urine. The intensity of the pain is not always proportional to the size of the stone; a small, jagged stone can cause more severe pain than a larger but smooth stone.
Adequate hydration —generally around 2 liters per day spread out over the course of the day—remains the most well-documented preventive measure: it dilutes the urine and limits the concentration of substances that can form crystals. This recommendation applies to all types of stones, regardless of their composition, and should be adjusted for heat, physical activity, and individual fluid loss.
In addition to hydration, certain dietary adjustments can reduce the risk of recurrence depending on the type of stone identified: reducing oxalate intake (spinach, chocolate, strong tea) for calcium stones; moderation in salt and animal protein intake; and maintaining normal calcium intake (excessive restriction of dietary calcium is not recommended, as it paradoxically promotes oxalate absorption). Magnesium is one of the protective factors naturally present in urine that limit calcium crystallization.
Certain herbs traditionally used to support urinary comfort can be part of a preventive approach, in addition to staying hydrated—but not as a substitute for it. Bearberry is traditionally used to support urinary tract health; however, it should be limited to short-term use due to its content of compounds that require monitoring over the long term.
Emergency care is necessary in cases of fever accompanied by lower back pain (suspected infection due to an obstruction, a urological emergency), total inability to urinate, pain not relieved by standard pain relievers, or a stone in a person with only one functioning kidney. Apart from these emergency situations, a scheduled appointment is still necessary to analyze the passed stone and implement long-term preventive measures, such as selecting products designed to promote daily urinary comfort.
