Un cálculo renal es un cristal duro que se forma cuando las sales de la orina se concentran lo suficiente como para precipitar fuera de la solución. Cerca de ocho de cada diez están hechos de calcio. A la mayoría de los cálculos se les puede evitar que vuelvan, y los cambios que lo logran son comida y líquido corrientes antes que cualquier medicación. El mayor es sencillo: beba lo suficiente para que la orina se mantenga clara, apuntando a más de dos litros de orina al día. En un ensayo aleatorizado, eso redujo aproximadamente a la mitad las recurrencias a lo largo de cinco años.
Los cambios de dieta que siguen son menos obvios. Mantener el calcio normal supera a reducirlo: el calcio ingerido con las comidas fija el oxalato en el intestino antes de que llegue a la orina. Comer menos sal y proteína animal junto con más productos ricos en potasio desplaza la orina en la misma dirección beneficiosa. Un cálculo que ya está en movimiento suele pasar por sí solo con líquidos y analgésicos, y un urólogo interviene cuando uno es demasiado grande para pasar. La única situación que no puede esperar es un cálculo que bloquea un riñón junto con fiebre o escalofríos, que puede volverse séptico en cuestión de horas.
Practice Ranking
Every practice we track for Kidney Stones: What They Are and What Keeps Them From Coming Back, ranked by how well the evidence supports it for this condition. Strength describes the evidence, not our endorsement.
6 practices · 2 to start with
| # | Practice | Evidence | Type | Cost | Effort | Results In | Add to plan |
|---|---|---|---|---|---|---|---|
| 1 | Hydration and Electrolytes: How Much Water You Need, and When Salt Actually Matters High fluid intake more than halved five-year recurrence; drinking enough to keep urine pale is the single most effective thing a stone-former can do. | Strong | Self-Directed | Free to $ | Easy | Days | |
| 2 | Sodium Reduction & DASH Diet: What Lowers Blood Pressure, and How to Do It Cutting salt and animal protein while keeping normal dietary calcium halved relapses, and a DASH-style pattern tracked with 40 to 45% fewer stones. Get calcium from food, not pills. | Strong | Self-Directed | Free to $ | Moderate | Days to Weeks | |
| 3 | Caffeine: What It Does, the One Catch for Sleep, and How to Use It Well Higher caffeine intake was linked with 26 to 31% fewer stones; coffee and tea count toward fluids rather than against them. | Moderate | Self-Directed | Free to $ | Easy | Days | |
| 4 | Reduce Vitamin C: What It Actually Does, Colds, and the Right Dose High-dose vitamin C raised stone risk in men but not women, so stone-forming men are better keeping supplemental vitamin C modest. | Moderate | Supplement | $ | Easy | Days | |
| 5 | Weight Loss: The Single Strongest Lever for Metabolic Health, and What the Trials Actually Show Reduces stone risk where obesity is a factor, alongside fluids. | Moderate | Self-Directed | Free to $$$ | Moderate to Hard | Weeks to Months | |
| 6 | Acupuncture: What the Evidence Shows, Where It Helps Most, and How to Start Used for acute renal-colic pain relief. | Emerging | Self-Directed | Free to $$$ | Easy to Moderate | Weeks to Months | |
Default order puts the best-supported practices first, with self-directed care ahead of clinical options. Click any row to open the practice.
What It Is
Urine carries stone-forming salts such as calcium and oxalate. It also carries the things that keep those salts dissolved: mainly water and citrate. When the urine is scarce or the balance tips, the salts join into crystals, and the crystals grow into a stone. The two biggest levers are how much urine you make and what is dissolved in it, and both are largely within your control.
Stones come in four kinds, and the kind you make changes the plan:
- Calcium stones are about eight in ten of them, mostly calcium oxalate with some calcium phosphate. The fluid and diet advice here is built for them.
- Uric-acid stones form in urine that is too acidic and are more common with excess weight, gout, a high animal-protein intake and diabetes. They are the one type that can sometimes be dissolved, by lowering the urine's acidity.
- Struvite stones grow out of certain urinary infections, can build into large branching staghorn stones, and mostly affect women. Diet does not touch them; they clear only by treating the infection and removing the stone.
- Cystine stones come from an inherited condition, cystinuria, in which extra cystine passes into the urine. They start in childhood, keep returning, and need specialist care.
Roughly one person in ten forms a stone at some point. After a first calcium stone, close to half of people form another within five to ten years if nothing changes. That recurrence is the part you can act on, because the same measures that lower the odds of a second stone are cheap, safe, and mostly ordinary food and water. The first stone usually comes as sudden pain with no warning; the second is far more preventable.
How to Keep Stones Away
Prevention runs in a clear order. Fluid comes first, because it is the best proven and easiest. Diet changes come next, and several run against old advice. Medication comes last, after a 24-hour urine test shows what your own chemistry needs.
Fluid is the foundation. In a five-year randomized trial, people who kept urine output above two liters a day had a 12% recurrence rate, against 27% with no specific advice. They also went nearly a year longer before a new stone. Pale urine is the at-home gauge that you are drinking enough. In hot weather or hard physical work you need more to reach the same output.
No pill for stones is as well proven, or as free.
The diet changes reshape what is dissolved in that urine, and the first one is counter-intuitive. For decades, people who formed calcium stones were told to cut calcium, and it backfired. Calcium eaten with a meal binds oxalate in the gut and carries it out in the stool, so less oxalate reaches the urine. In a five-year trial, men with recurrent calcium-oxalate stones kept calcium normal at about 1,200 mg a day while cutting salt and animal protein. They had half the relapses of men on the traditional low-calcium diet. Their urinary oxalate fell, while the low-calcium group's rose. In large cohorts, people eating the most dietary calcium formed fewer stones, while calcium pills taken away from food carried a small rise in risk in women. Calcium supplements are fine; take them with a meal.
The other levers each shift urine chemistry in a measurable way:
- Less salt. Sodium raises the calcium in your urine, so cutting salt lowers the urinary calcium that helps stones form. In a large cohort of women, the highest sodium intake tracked with more stones.
- Less animal protein. A high animal-protein intake makes the urine more acidic and raises both calcium and uric acid while lowering the protective citrate. In the men's cohort, the highest animal-protein intake carried about a third more stones.
- More potassium-rich produce. Fruit and vegetables raise urinary citrate, the molecule that keeps calcium and oxalate from crystallizing. Citrus fruit and its juice add citrate directly. That is why lemon water helps.
- A DASH-style plate. People whose everyday eating most resembled the DASH pattern formed roughly 40 to 45% fewer stones across three large cohorts. The pattern is heavy on produce, potassium and low-fat dairy, light on salt, sugar and red meat. The benefit held even in those eating less calcium.
- Less sugary soda. Sugar-sweetened soda raised stone risk 23 to 33%, while coffee, tea, wine, beer and citrus juice each tracked with fewer stones. The fructose and sodium built into sugary drinks and processed food raise both metabolic risk and, by way of the urine, the risk of a stone.
- A healthy weight. Higher body weight and adult weight gain raise risk, more so in women.
Medication has a place, and it comes after the basics and a urine test. For repeat stone formers whose 24-hour urine shows low citrate, potassium citrate nearly stopped new stones in a three-year trial. It dropped the rate from 1.2 to 0.1 stones a year. It can also help dissolve uric-acid stones by making the urine less acidic.
Thiazide water pills are the other long-standing prescription, given to lower urinary calcium, and the evidence has shifted. A large, careful 2023 trial found that hydrochlorothiazide did not clearly beat a dummy pill for preventing recurrence at any dose. A prescriber now weighs it case by case. A guideline review ranked them: extra fluid roughly halved recurrence for everyone. For people with several past stones, adding a citrate, a thiazide or allopurinol on top of fluid reduced it further.
The Research & Studies
Everything here is based on the research we have collected and checked, sorted into groups and ordered with the strongest evidence first. Click any claim to open the studies behind it.
Kidney Stones
Una alta ingesta de líquidos redujo la recurrencia a cinco años al 12.1 % desde el 27.0 %
Las personas que bebían suficiente agua para mantener su orina pálida tuvieron aproximadamente la mitad de nuevos cálculos a lo largo de cinco años que quienes no lo hicieron.
199 personas con un primer cálculo de calcio idiopático fueron asignadas aleatoriamente a beber lo suficiente para mantener la producción de orina por encima de 2 litros al día o a ningún consejo específico, y seguidas durante 5 años. La recurrencia fue del 12.1 % en el grupo de alto líquido frente al 27.0 % en el grupo control, y el tiempo promedio hasta un nuevo cálculo fue mayor, 38.7 frente a 25.1 meses. Measured in: 199 adults after a single idiopathic calcium stone, no drug treatment, followed for 5 years in Parma, Italy.. Un único ensayo de un solo centro en personas que formaban cálculos por primera vez, por lo que habla mejor a alguien temprano en el curso, no a una persona con muchos cálculos pasados. Fue de etiqueta abierta, como debe ser un estudio de agua, y mide lo que lograron las personas que aceptaron beber más, no una pastilla tomada según un horario.
Who this may not transfer to:Both sexes were enrolled; the trial did not report recurrence separately by sex.
The study · 1
Borghi et al., urinary volume, water and recurrences in idiopathic calcium nephrolithiasis: a 5-year randomized prospective study · J Urol 1996;155(3):839-43
El calcio normal con menos sal y proteína animal redujo a la mitad las recaídas frente a una dieta baja en calcio (RR 0.49)
Los hombres que mantuvieron el calcio normal y redujeron la sal y la carne tuvieron aproximadamente la mitad de recaídas de cálculos que los hombres puestos en una dieta baja en calcio.
120 hombres con cálculos recurrentes de oxalato de calcio y calcio urinario alto fueron asignados aleatoriamente durante 5 años a una dieta con calcio normal (aproximadamente 1200 mg/día) más sal y proteína animal reducidas, o a la dieta tradicional baja en calcio (aproximadamente 400 mg/día). Las recaídas fueron 12 de 60 con la dieta de calcio normal frente a 23 de 60 con la dieta baja en calcio, un riesgo relativo de 0.49 (IC del 95 %: 0.24 a 0.98). El oxalato urinario bajó con la dieta de calcio normal y subió con la baja en calcio. Measured in: 120 men with recurrent calcium-oxalate stones and idiopathic hypercalciuria, followed 5 years.. Este es el ensayo que revirtió el viejo consejo de bajo calcio, y estudió a hombres con una química de cálculo específica, oxalato de calcio con calcio urinario alto. Reducir el calcio dietético deja que más oxalato cruce el intestino y llegue a la orina, que es el mecanismo que expuso. La comparación fue frente a una dieta baja en calcio, no frente a comer libremente.
Who this may not transfer to:Only men were enrolled. Urinary calcium and oxalate handling differ with sex and after menopause, so the size of the benefit in women is not established here, though the same mechanism, dietary calcium binding oxalate in the gut, applies to both.
The study · 1
Borghi et al., comparison of two diets for the prevention of recurrent stones in idiopathic hypercalciuria · N Engl J Med 2002;346(2):77-84
La hidroclorotiazida no superó al placebo en la recurrencia (59 % con placebo, 49 % a 59 % con el fármaco)
Una pastilla diurética prescrita durante mucho tiempo para prevenir cálculos no superó claramente a una pastilla ficticia en un gran ensayo moderno.
416 personas con cálculos de calcio recurrentes fueron asignadas aleatoriamente a hidroclorotiazida a 12.5, 25 o 50 mg diarios o a placebo y seguidas durante una mediana de 2.9 años. Una recurrencia de cálculo ocurrió en el 59 % con placebo y en el 59 %, 56 % y 49 % en las tres dosis, sin una relación dosis-respuesta significativa y sin una separación clara del placebo. Measured in: 416 adults with recurrent calcium-containing stones, Switzerland, median 2.9 years.. Las tiazidas sí bajan el calcio urinario y ensayos más antiguos y pequeños sugirieron que reducían la recurrencia, razón por la cual las guías las recomiendan. Este ensayo grande y bien realizado no confirmó eso, por lo que es una pregunta abierta, no una respuesta asentada, y quien prescribe lo sopesa caso por caso.
Who this may not transfer to:Both sexes enrolled; the null result applied across the trial.
The study · 1
Dhayat et al., hydrochlorothiazide and prevention of kidney-stone recurrence · N Engl J Med 2023;388(9):781-91
El líquido adicional redujo aproximadamente a la mitad la recurrencia; los fármacos ayudan a quienes forman cálculos repetidos (ensayos combinados)
Al reunir los ensayos, beber más es la base que redujo aproximadamente a la mitad la recurrencia para todos, y para quienes forman cálculos repetidos, un citrato, una pastilla diurética o alopurinol añade más.
Una revisión sistemática de 28 ensayos aleatorizados para una guía del American College of Physicians encontró que en personas con un cálculo de calcio pasado, aumentar la ingesta de líquidos redujo aproximadamente a la mitad la recurrencia (riesgo relativo de 0.45) y reducir los refrescos la bajó (RR 0.83). En personas con varios cálculos pasados, la mayoría ya bebiendo más, añadir una tiazida (RR 0.52), citrato (RR 0.25) o alopurinol (RR 0.59) además del líquido redujo aún más la recurrencia, con el beneficio del alopurinol limitado a quienes tenían ácido úrico alto. Measured in: Adults with calcium stones, pooled across randomized and controlled trials in the review.. La revisión es anterior al ensayo NOSTONE de 2023, que no confirmó el beneficio de la tiazida, por lo que las conclusiones sobre líquido y citrato se han sostenido mejor que la de la tiazida. Establece el orden de operaciones: líquidos primero, fármacos dirigidos segundo.
Who this may not transfer to:Pooled from trials enrolling both sexes; conclusions were not split by sex.
The study · 1
Fink et al., medical management to prevent recurrent nephrolithiasis in adults: a systematic review for an American College of Physicians Clinical Guideline · Ann Intern Med 2013;158(7):535-43
Los hombres que comían más calcio dietético formaron menos cálculos (RR 0.66)
Los hombres que comían el alimento más rico en calcio, en su mayoría lácteos, formaron menos cálculos que los hombres que comían menos, mientras que más carne significó más cálculos y más producto fresco y líquido significó menos.
En 45,619 hombres seguidos durante 4 años, los hombres que comían más calcio dietético tuvieron un menor riesgo de un cálculo sintomático que los hombres que comían menos, riesgo relativo de 0.66 (IC del 95 %: 0.49 a 0.90) tras el ajuste. En la misma cohorte, una mayor ingesta de proteína animal elevó el riesgo (RR 1.33), mientras que un mayor potasio (RR 0.49) y un mayor líquido (RR 0.71) lo redujeron. Measured in: 45,619 male health professionals aged 40 to 75 with no history of stones at baseline, followed 4 years.. What could explain it instead: Men who eat more dairy calcium and produce and less meat tend to differ in overall diet quality, weight, and activity, any of which affects stone risk. The study adjusted for many of these, but a healthier-eater pattern cannot be fully separated from the calcium itself.. Una cohorte observacional, por lo que muestra un patrón, no una prueba, pero apunta en la misma dirección que los ensayos dietéticos posteriores, razón por la cual tiene peso.
Who this may not transfer to:Men only in this cohort; the companion Nurses' Health Study found the same inverse relationship for dietary calcium in women.
The study · 1
Curhan et al., a prospective study of dietary calcium and other nutrients and the risk of symptomatic kidney stones · N Engl J Med 1993;328(12):833-8
En mujeres, el calcio de los alimentos significó menos cálculos (RR 0.65), las pastillas de calcio ligeramente más (RR 1.20)
Las mujeres que obtenían su calcio de los alimentos tuvieron menos cálculos, pero las mujeres que tomaban pastillas de calcio, a menudo entre comidas, tuvieron ligeramente más.
Entre 91,731 mujeres seguidas durante 12 años con 864 cálculos, las del quinto más alto de calcio dietético tuvieron un riesgo menor que las del quinto más bajo (RR 0.65; IC del 95 %: 0.50 a 0.83), mientras que las mujeres que tomaban suplementos de calcio tuvieron un riesgo ligeramente más alto que las no usuarias (RR 1.20; IC del 95 %: 1.02 a 1.41). Un mayor líquido (RR 0.61) y potasio (RR 0.65) redujeron el riesgo; más sacarosa (RR 1.52) y sodio (RR 1.30) lo elevaron. Measured in: 91,731 women in the Nurses' Health Study, followed 12 years.. What could explain it instead: Women who take calcium pills differ from those who do not in age, bone health, and reason for supplementing, and supplement users may take them apart from meals. These differences, not the calcium alone, could carry part of the higher risk seen with pills.. La división entre el calcio de los alimentos ayudando y el calcio en pastilla no ayudando encaja con el momento: el calcio comido con una comida se une al oxalato en el intestino antes de que llegue a la orina, mientras que un suplemento tomado lejos de la comida no lo hace. No significa que deban evitarse los suplementos de calcio, solo que es mejor tomarlos con las comidas.
Who this may not transfer to:Women only here; the men's cohort showed the same protective pattern for dietary calcium, so the food-calcium finding travels across sexes.
The study · 1
Curhan et al., comparison of dietary calcium with supplemental calcium and other nutrients as factors affecting the risk for kidney stones in women · Ann Intern Med 1997;126(7):497-504
La obesidad elevó el riesgo de cálculos, de un riesgo relativo de 1.33 en hombres a 2.09 en mujeres más jóvenes
Cargar más peso, y ganar peso a lo largo de la adultez, hace más probables los cálculos, y el efecto se ve mayor en mujeres.
En tres grandes cohortes con 4827 cálculos, un IMC de 30 o más, en comparación con 21 a 22.9, conllevó un riesgo relativo de 1.33 en hombres, 1.90 en mujeres mayores y 2.09 en mujeres más jóvenes. Ganar más de 16 kg (aproximadamente 35 lb) desde la adultez temprana elevó el riesgo en un 39 % en hombres y un 70 % a 82 % en mujeres. Measured in: Men in the Health Professionals Follow-up Study and women in Nurses' Health Studies I and II, 46 years of combined follow-up.. What could explain it instead: People with higher BMI differ in diet, especially sugar, salt and animal protein, and in fluid intake, all independent stone risks. The analysis adjusted for these, but weight tracks with a whole cluster of habits that raise risk.. La obesidad cambia la química de la orina, elevando el calcio, el oxalato y el ácido úrico y bajando el pH, por lo que el vínculo es biológicamente plausible además de estadístico. Se espera que perder peso ayude por las mismas razones, aunque estas cohortes midieron el riesgo con el peso, no el efecto de perderlo.
Who this may not transfer to:Both sexes studied in parallel cohorts; the increase in risk with weight was consistently larger in women than in men.
The study · 1
Taylor et al., obesity, weight gain, and the risk of kidney stones · JAMA 2005;293(4):455-62
El refresco azucarado elevó el riesgo de cálculos del 23 % al 33 %
Las personas que bebían más refresco azucarado formaron más cálculos, mientras que el café, el té y el jugo de cítricos fueron en la otra dirección.
Entre 194,095 personas con 4462 cálculos, la mayor ingesta de cola azucarada conllevó un riesgo un 23 % más alto de un cálculo que la más baja, y las bebidas no de cola azucaradas un riesgo un 33 % más alto. En el mismo análisis, el café, el té, el vino, la cerveza y el jugo de naranja se vincularon cada uno con un menor riesgo. Measured in: 194,095 participants pooled from three US cohorts, median follow-up over 8 years.. What could explain it instead: Heavy soda drinkers differ in weight, total diet and activity from people who drink coffee or juice, and those differences drive stone risk on their own. Adjustment reduces but does not remove this.. No todo líquido cuenta igual. El viejo consejo de 'beber más de lo que sea' es demasiado tosco: las bebidas azucaradas, especialmente las endulzadas con fructosa, se corresponden con más cálculos, mientras que varias bebidas sin azúcar se corresponden con menos.
Who this may not transfer to:Men and women pooled; beverage associations were consistent across the cohorts.
The study · 1
Ferraro et al., soda and other beverages and the risk of kidney stones · Clin J Am Soc Nephrol 2013;8(8):1389-95
Una dieta estilo DASH se vinculó con un 40 a 45 % menos de cálculos (RR 0.55 a 0.60)
Las personas cuya alimentación cotidiana se parecía al patrón DASH, mucho producto fresco y lácteos, poca sal, refresco y carne roja, tuvieron aproximadamente un 40 a 45 % menos de cálculos.
En tres cohortes con 5645 cálculos, las personas que comían más parecido al patrón DASH (rico en fruta, verduras, frutos secos, legumbres, lácteos bajos en grasa y granos integrales, bajo en sal, bebidas azucaradas y carne roja) tuvieron un riesgo menor que quienes comían menos parecido: riesgo relativo de 0.55 en hombres, 0.58 en mujeres mayores y 0.60 en mujeres más jóvenes. El beneficio se mantuvo incluso en personas con menor ingesta de calcio. Measured in: 241,766 adults across the Health Professionals Follow-up Study and Nurses' Health Studies I and II, up to 18 years of follow-up.. What could explain it instead: People who eat a DASH-style diet tend to be leaner, more active and more health-conscious overall. The study adjusted for BMI and fluid, but the dietary pattern still travels with a healthier life.. La DASH agrupa la mayoría de las palancas individuales, más producto fresco y potasio, más calcio lácteo, menos sal, azúcar y carne, en un solo patrón, razón por la cual el efecto es mayor que cualquier cambio único por sí solo. Es una forma de comer completa, no un suplemento.
Who this may not transfer to:Both sexes studied; the reduction in risk was close to identical for men and women.
The study · 1
Taylor et al., DASH-style diet associates with reduced risk for kidney stones · J Am Soc Nephrol 2009;20(10):2253-9
El citrato de potasio redujo los nuevos cálculos de 1.2 a 0.1 al año en quienes formaban cálculos con bajo citrato
Un suplemento de citrato, que hace la orina menos propicia para los cálculos, casi detuvo los nuevos cálculos en personas cuya orina tenía poco citrato.
57 personas con cálculos recurrentes de calcio y bajo citrato urinario fueron asignadas aleatoriamente a citrato de potasio (30 a 60 mEq/día) o placebo durante 3 años. En el grupo tratado, la formación de nuevos cálculos bajó de 1.2 a 0.1 cálculos por persona al año y 13 de 18 (72 %) entraron en remisión, mientras que el grupo placebo se mantuvo en aproximadamente 1.1 al año con solo 4 de 20 (20 %) en remisión. Measured in: 57 adults with active recurrent calcium stones and hypocitraturia, 3-year randomized trial.. Esto funciona para un grupo específico, personas cuya orina de 24 horas muestra bajo citrato, razón por la cual conocer la química de su orina importa antes de recurrir a él. Es un ensayo pequeño, y la vía alimentaria hacia el mismo fin, cítricos y productos frescos, también eleva el citrato urinario.
Who this may not transfer to:Both sexes typical of a calcium-stone clinic; the trial did not report results split by sex, and the sample is small.
The study · 1
Barcelo et al., randomized double-blind study of potassium citrate in idiopathic hypocitraturic calcium nephrolithiasis · J Urol 1993;150(6):1761-4
La vitamina C en dosis altas elevó el riesgo de cálculos en hombres (razón de riesgo instantáneo de 1.43), no en mujeres
Los hombres que tomaron pastillas de vitamina C en dosis altas formaron más cálculos; la vitamina C de los alimentos no elevó el riesgo, y el efecto no se observó en mujeres.
En 197,271 personas con 6245 cálculos, una alta ingesta total de vitamina C se vinculó con más cálculos en hombres (1000 mg/día o más frente a menos de 90, razón de riesgo instantáneo de 1.43; IC del 95 %: 1.15 a 1.79) y la vitamina C en suplemento a 1000 mg/día o más con una razón de riesgo instantáneo de 1.19 (IC del 95 %: 1.01 a 1.40). No apareció asociación significativa en mujeres, y la vitamina C dietética de los alimentos no se vinculó con cálculos en ninguno de los sexos. Measured in: 40,536 men and 156,735 women in three US cohorts, median follow-up about 11 years.. What could explain it instead: High-dose supplement users differ from non-users in health beliefs and other habits. The analysis adjusted for BMI, thiazide use and diet, and the food-versus-pill split argues for a real dose effect, but residual confounding remains possible.. El cuerpo convierte parte de la vitamina C en oxalato, que es la vía plausible hacia más cálculos de oxalato de calcio, y aparece con los suplementos, no con los alimentos, porque las dosis en suplemento son mucho más altas. La vitamina C de la fruta y las verduras no conllevó riesgo.
Who this may not transfer to:Both sexes studied; the higher risk with high-dose vitamin C reached significance in men but not in women.
The study · 1
Ferraro et al., total, dietary, and supplemental vitamin C intake and risk of incident kidney stones · Am J Kidney Dis 2016;67(3):400-7
La mayor cafeína se vinculó con un 26 a 31 % menos de cálculos
Las personas que consumían más cafeína, principalmente del café, formaron menos cálculos, y su orina parecía menos propensa a los cálculos.
En 217,883 personas con 4982 cálculos, quienes estaban en el quinto más alto de ingesta de cafeína tuvieron un menor riesgo de un cálculo que el quinto más bajo: un 26 % menos en hombres, un 29 % y un 31 % menos en las dos cohortes de mujeres. En un subestudio de orina, más cafeína se correspondió con un mayor volumen de orina y una menor sobresaturación de oxalato de calcio. Measured in: 217,883 adults across three US cohorts, median follow-up over 8 years.. What could explain it instead: Coffee and caffeine drinkers differ from abstainers in weight and diet. The study adjusted for fluid intake and BMI, and the supporting urine chemistry strengthens the case, but this remains an association.. El beneficio se mantuvo incluso en personas que bebían poco café con cafeína, lo cual apunta a la cafeína en sí misma, no solo al líquido. Es una razón para no temer al café, no una razón para cargar de cafeína, y una ingesta muy alta conlleva sus propias desventajas.
Who this may not transfer to:Both sexes studied; the lower risk was consistent for men and women.
The study · 1
Ferraro et al., caffeine intake and the risk of kidney stones · Am J Clin Nutr 2014;100(6):1596-603
Un extracto de Jin Qian Cao redujo la acumulación de cristales renales en ratas
En un estudio en ratas, un extracto de la hierba china para cálculos Jin Qian Cao redujo cuántos cristales se acumulaban en el riñón.
En ratas a las que se dio una sustancia química que impulsa la formación de cristales de oxalato de calcio, los flavonoides totales de Desmodium styracifolium redujeron el depósito de cristales en el riñón y disminuyeron el daño de las células renales en comparación con los animales no tratados. Measured in: A hydroxy-L-proline rat model of calcium-oxalate urolithiasis.. Jin Qian Cao (Desmodium, 'hierba de moneda dorada') es la hierba a la que más recurre la medicina china en la enfermedad de cálculos, y el uso tradicional tiene siglos de antigüedad. El respaldo moderno hasta ahora es trabajo de laboratorio y animal más pequeñas series humanas, no los grandes ensayos humanos que tienen las palancas dietéticas, por lo que corresponde junto a ellas, no por delante, y los productos herbales vendidos en línea pueden estar mal etiquetados o adulterados.
Who this may not transfer to:An animal model. It shows a plausible mechanism, not an effect measured in people.
The study · 1
Zhou et al., total flavonoids of Desmodium styracifolium attenuates the formation of hydroxy-L-proline-induced calcium oxalate urolithiasis in rats · Urolithiasis 2018;46(3):231-241
Pain
Acupuncture eased renal-colic pain faster than an injected anti-inflammatory (85% versus 61% relieved)
Para el dolor súbito e intenso de pasar un cálculo, la acupuntura alivió el dolor más rápido y más completamente que un antiinflamatorio inyectado, aproximadamente el 85 % aliviado frente al 61 %, con una tasa similar de efectos secundarios.
In a double-blind single-center trial, 80 adults with acute renal colic from a ureteric stone received either acupuncture at SP6 and SP9 or an intramuscular injection of the anti-inflammatory lornoxicam. The short-term response rate was about 85% (33 of 39) with acupuncture against 61% (25 of 41) with the drug (P<0.001), and pain fell faster with acupuncture. Side effects were uncommon and similar in both groups (2.6% versus 7.3%, not a significant difference). Measured in: Adults presenting with acute renal colic from a ureteric stone, single randomized trial.. This is about controlling the pain of a stone already on the move, not about dissolving or preventing stones. It is a single trial and acupuncture pain studies are hard to blind. It sits alongside standard pain relief, and severe colic with fever or no urine still needs urgent care.
Who this may not transfer to:Both sexes present with colic; the trial reported pain outcomes for the whole group.
The study · 1
Zhang et al., acupuncture versus lornoxicam in the treatment of acute renal colic: a randomized controlled trial · J Pain Res 2021;14:3637-48
Know Your Stone and Your Urine
General advice prevents most stones. Two cheap tests turn that general advice into a plan aimed at you:
- A stone analysis. Catch a passed stone in a strainer and have it analyzed. The plan for a calcium-oxalate stone, a uric-acid stone and a cystine stone differ.
- A 24-hour urine test. It measures your own volume, calcium, oxalate, citrate, uric acid and acidity, then points to the lever that helps most. Low citrate points toward potassium citrate, high oxalate toward the calcium-with-meals fix, and low volume toward more fluid.
You can order both a stone analysis and a 24-hour urine test through direct-to-consumer testing, without waiting for a referral. For anyone who keeps forming stones despite the fluid and diet work, this is the step that ends the cycle. It stops the endless loop of general advice with no reason behind it.
Passing a Stone and When to Step In
A stone that reaches the ureter causes renal colic: sudden, severe, cramping pain from the flank or back toward the groin. Nausea and blood in the urine often come with it. Most small stones, roughly those under 5 mm, pass on their own within days to a few weeks. Stay well hydrated and control the pain, usually with an anti-inflammatory. For a larger stone lodged low in the ureter, an alpha-blocker such as tamsulosin can relax the passage and help it pass.
A urologist steps in when a stone is too large to pass on its own, when one has not moved after several weeks, or when it is blocking the kidney. The usual options break the stone up with shock waves from outside the body, or remove it through a thin scope passed up the urinary tract.
A few limits apply. Prevention lowers the odds of another stone but does not guarantee none; even people doing everything right can form one. The 2023 thiazide question stays unsettled. The whole plan rests on knowing your stone type, so the tests matter for anyone past a first stone.
What To Do First
None of this needs a prescription to begin, and it works alongside anything a prescriber has you on. Start with fluid, since it does the most for the least effort, and add the diet levers you can hold steadily. Save the medication step for after a urine test points to the lever you need.
Aim to pass more than two liters of urine each day, which roughly halved recurrence over five years after a first calcium stone. Pale urine is the gauge; in heat or hard work you need more. This is the single best-proven step and it costs nothing.
Do not cut calcium. Keep it near 1,200 mg a day from food, eaten with meals, so it binds oxalate in the gut; that halved relapses against a low-calcium diet. Pair it with less salt and animal protein. Both push calcium and stone-forming salts into the urine.
Produce puts citrate into your urine, the molecule that keeps crystals from clumping. Citrus and its juice add it directly. A produce-heavy, DASH-style plate tracked with 40 to 45% fewer stones in three cohorts.
Swap sugary soda for water, coffee or tea. Not every fluid counts the same; water and unsweetened drinks are the ones to lean on.
Extra weight raises urinary calcium, oxalate and acid, so shedding it lowers the odds of a stone. Steady loss held over months is what helps.
Two tests, a stone analysis and a urine collection over 24 hours, show your stone type and the lever that fits you. You can order both yourself through direct-to-consumer testing.
If stones keep coming despite the groundwork, or the urine test shows low citrate, potassium citrate and other targeted drugs add further protection. That decision follows the test, and a urologist handles a stone that will not pass.
Go Deeper
- Gout: uric-acid stones share their cause with gout, and the same fluid and diet levers help both.
- Sodium, potassium and the DASH diet: the eating pattern that shifted stone risk most, plate by plate.
- Coffee and caffeine: the drink linked with fewer stones, and how strong the link is.
- Vitamin C: useful from food, but why high-dose pills go the other way for stones.
- Weight and metabolic health: the lever underneath stone risk, and the habits that protect the kidneys and heart together.
The Chinese Medicine View
The Chinese Medicine View
Chinese medicine reads stones as Shi Lin (石淋), stone dribbling, one of the Lin syndromes of painful, difficult urination. The classical picture is Damp-Heat pouring down into the Bladder. Heat concentrates the fluids until they congeal, and the resulting gravel scrapes the passage. That matches the blood in the urine and the sharp pain a moving stone causes. The herb reached for most here is Jin Qian Cao (金钱草, Desmodium, 'golden coin grass'), long given to move stones and clear Damp-Heat. An extract of it cut crystal buildup in a rat model. The modern support is so far only laboratory, animal and small human series. It sits alongside the dietary levers, below them in strength. One caution: the cold, draining herbs used for an acute Damp-Heat attack are wrong for someone who is depleted and cold, with years of stones and fatigue. That picture is read instead as Kidney or Spleen deficiency.
The core stone pattern: painful, difficult, scanty urination, sometimes with gravel or blood, a sensation of heat, a yellow greasy tongue coat. The direction is to clear Damp-Heat, free the urine and move the stone.
The acute attack: sudden cramping pain radiating from the flank to the groin as a stone moves. The direction is to move Qi, relieve the spasm and stop pain. Acupuncture is most often used here. One trial found it eased colic pain faster than an injected anti-inflammatory.
Years of recurrent stones with lower-back and knee weakness, fatigue, and a pale tongue, a deficiency sign, where the acute Damp-Heat pattern shows red with a yellow coat. Here draining alone weakens further; the direction is to support the Kidneys while gently clearing what remains.
Cautions For This Practice
Extra restraintEverything to be aware of is here, in one place. This practice suits most healthy people; a few situations call for real care.
High-dose vitamin C pills, not the vitamin C in food
The body turns some vitamin C into oxalate, the salt that pairs with calcium in the commonest stones. In a large cohort, men taking 1,000 mg a day or more of total vitamin C formed more stones (hazard ratio 1.43). Vitamin C from fruit and vegetables carried no added risk, and the produce it comes in adds citrate that helps.
Potassium citrate and salt substitutes need working kidneys
Potassium citrate and potassium-based salt substitutes raise blood potassium. That is safe for most people but not for everyone. If your kidney function is reduced, or you take a potassium-sparing diuretic or an ACE inhibitor or ARB, too much potassium can build up. This is a question to run past a prescriber before starting, and a reason the medication step follows a urine test.
Herbal stone products sold online
Herbal products marketed to flush or dissolve stones have a documented history of mislabeling and, at times, adulteration. You often cannot know the dose, or what else is in the bottle. If you want to use a traditional herb such as Jin Qian Cao, use a traceable supply and a practitioner who knows the source.
Start slow, be smart, read the research, and consult a professional if you have any concerns. This is here to inform your choice, not make it for you.
When to See Someone
Most stone care happens calmly at home, and passing a stone, while painful, is usually not dangerous. A few situations are different and need help quickly, one of them the same hour:
- Flank or back pain with a fever or chills, or shaking, which can mean a stone is blocking a kidney that is now infected. A blocked, infected kidney can turn septic within hours and is a same-day emergency(seek urgent care)
- Not being able to pass any urine at all, especially with pain in both sides, which can mean both kidneys or a single kidney is obstructed(seek urgent care)
- Pain so severe you cannot keep down fluids, or that is not controlled by ordinary pain relief, or that comes with persistent vomiting(seek urgent care)
- Visible blood in the urine for the first time, which usually is a stone but needs checking to rule out other causes
- A stone that has not passed after several weeks, or one your imaging shows is too big to pass by itself, which a urologist can break up or remove
- Stones that keep returning even with steady fluid and diet work. That is the signal to test the stone itself and collect a 24-hour urine sample, then aim the plan at your own chemistry
- Stones starting in childhood, a strong family history, or a single functioning kidney, all of which change how closely things should be watched
None of this is meant to worry you. Kidney stones are common, most pass on their own, and most people can cut how often they come back with the steps above. The urgent signs are the exception, and knowing them means you can act calmly on the rest.
Common Questions
What actually causes kidney stones?
Concentrated urine. A stone appears when the salts your urine carries, chiefly calcium and oxalate, grow concentrated enough to crystallize instead of staying dissolved. Roughly eight in ten stones are calcium-based. It happens when there is too little water and citrate to keep those salts dissolved. Rich food, salt and too little fluid tip the balance; no single food creates a stone on its own.
What is the single best thing I can do to prevent them?
Drink more water, until your urine runs pale through the day. That usually means passing more than two liters daily. It is the best-proven step there is: a randomized trial cut recurrence roughly in half over five years. Heat and hard physical work mean drinking still more to hit the same target.
Should I cut out calcium or dairy?
No: cutting calcium usually makes calcium stones more likely. Calcium taken with a meal grabs oxalate in the gut, so less of it reaches the urine, where it would otherwise join with calcium into a stone. That is why about 1,200 mg of calcium a day from food beat a low-calcium diet in the trials, not the reverse. Get it from food with meals; pills swallowed apart from meals nudged risk up slightly in women.
Do I have to avoid spinach and other oxalate foods?
Not by banning them. What matters more is pairing oxalate foods with calcium at the same meal, so the calcium ties up the oxalate in the gut. Have spinach with dairy, and keep eating produce for the protective citrate it raises. The exception is the high-dose vitamin C pill. The body converts a little of it to oxalate, and men taking 1,000 mg or more a day formed more calcium stones. The vitamin C in food added no risk.
Does lemon water or citrate actually help?
Yes, modestly. Citrate keeps calcium and oxalate from clumping into a crystal, and lemon and other citrus put it straight into the urine. When a repeat former's 24-hour test comes back low in citrate, prescription potassium citrate does far more. In a three-year trial it nearly eliminated new stones, cutting the yearly rate almost to zero, about 0.1 a year.
Are kidney stones linked to gout?
Yes, through uric acid. Uric-acid stones need acidic urine to form, the same high-urate, acidic ground that drives gout, so the two often travel together. Weight, a lower animal-protein intake and plenty of fluid help both. Uric-acid stones are also the one kind you can sometimes dissolve, by raising the urine's pH with potassium citrate.
All 14 sources on this page independently checked and cross-referenced.
Thomas Dehli, Founder & Editor, Sacred Lotus
Sacred Lotus has published Chinese medicine reference material since 2001. Integrative pages are held to the same standard as the herb and formula library: cite the source, grade the claim at its real strength, and say where the research has not looked. This page is educational and it is not medical advice. Last reviewed and updated August 9, 2026.
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