Does Drinking More Water Help Prevent Kidney Stones?

For people who have had a kidney stone, drinking more water is one of the most effective and best-studied ways to lower the odds of another one. The reason is simple plumbing: stones form when the salts in urine become concentrated enough to crystallize, and diluting your urine by drinking more keeps those salts in solution so they never get the chance. It is not a folk remedy — it is a first-line recommendation backed by a randomized trial.

How stones form, and why dilution matters

Kidney stones start as tiny crystals of minerals like calcium oxalate that clump together when urine is too concentrated. Think of stirring sugar into iced tea: a small amount dissolves, but past a point it settles at the bottom. Concentrated urine works the same way — the more crystal-forming material packed into a small volume of fluid, the more likely it is to precipitate and grow. Drinking more water increases your urine volume, thins that solution, and lowers the concentration of stone-forming salts so crystals stay dissolved and get flushed out.

What the research shows

The landmark evidence is a five-year randomized trial of people who had passed a first calcium stone. Those coached to drink enough water to produce a higher urine volume had a recurrence rate of about 12% over five years, compared with about 27% in the group that did not change their intake — and among those who did have another stone, it took longer to appear (Borghi et al., 1996, Journal of Urology, reviewed in Investigative and Clinical Urology). A later meta-analysis of fluid-intake studies reached the same conclusion: higher water intake is associated with a meaningfully lower risk of stone recurrence (Cheungpasitporn et al., 2015, Medicine (Baltimore)). Roughly halving the recurrence rate with something as accessible as water is a strong result.

How much is "enough"?

The target is defined by output, not just input. Guidelines generally aim for a urine volume of at least 2 to 2.5 liters a day, which for most people means drinking somewhere around 2.5 to 3 liters of fluid daily, since some is lost through skin and breath. The practical signal is your urine color: consistently pale, near-clear yellow means you are likely diluting well, while dark yellow is a cue to drink more. Spreading intake across the whole day matters too — urine gets most concentrated overnight and during long gaps, so steady sipping beats one or two big gulps.

A few honest caveats

Water is powerful for prevention, but it is not the whole story. The type of stone and its underlying cause matter — diet, certain medical conditions, and specific minerals in your stones can all play a role, which is why a doctor may recommend dietary changes or testing beyond "drink more." And a recent large trial found that a coaching program aimed at boosting fluid intake did not reduce stones as much as hoped, largely because sustaining higher intake over time is hard. The lesson is not that water fails — it is that the benefit depends on actually keeping urine dilute day after day, which takes a habit and a system.

The setup that makes the habit stick

Hitting a higher urine volume is really a consistency problem, and a bottle you refill on a schedule solves it. A NuRich 32 oz Insulated Water Bottle ($29.99) turns the goal into something countable — two to three fills gets most people into the target range, and the insulation keeps it cold enough that you actually want to drink it. Keep a NuRich 18 oz Insulated Water Bottle ($14.99) by the bed or in the car so the overnight and commuting gaps get covered too. Browse the full lineup at the NuRich collection.

The bottom line

If you are prone to kidney stones, drinking enough water to keep your urine pale and your volume up is one of the highest-value habits you can build — a landmark trial cut recurrence roughly in half. Aim for steady intake across the day, use urine color as your gauge, and loop in your doctor about stone type and diet. Dilution is the whole game, and water is how you win it.

This article is for general informational purposes only and is not medical advice. If you have had kidney stones or a kidney condition, talk with your healthcare professional before making major changes to your fluid intake.

Sources: Borghi L et al., "Urinary volume, water and recurrences in idiopathic calcium nephrolithiasis: a 5-year randomized prospective study," J Urol, 1996 (reviewed in Investig Clin Urol); Cheungpasitporn W et al., "Self-Fluid Management in Prevention of Kidney Stones: A meta-analysis," Medicine (Baltimore), 2015.