Most kidney stones smaller than 5 mm will pass on their own without any procedure, and there are several evidence-backed strategies that can help speed the process or prevent stones from growing. True dissolution, where a stone actually breaks apart chemically, is only reliably possible with one type of stone: uric acid stones. For the more common calcium oxalate stones, “natural” management focuses on helping the stone pass, preventing it from getting bigger, and reducing your risk of new ones.
Which Stones Can Actually Pass on Their Own
Size is the single biggest factor in whether a stone will pass without intervention. Research published in the American Journal of Roentgenology tracked spontaneous passage rates by stone size: stones 1 to 4 mm passed on their own about 76% of the time, stones 5 to 7 mm passed about 60% of the time, and stones 8 mm or larger dropped to roughly 48% or less. Once a stone hits 10 mm, the spontaneous passage rate falls to around 25%.
If your stone is under 5 mm, your doctor will likely recommend a “watchful waiting” approach with pain management and the strategies below. Stones between 5 and 10 mm are a gray zone where these methods may help, but you’ll need close follow-up. Anything over 10 mm almost always requires a procedure.
Drink Enough to Produce Clear Urine
Fluid intake is the single most effective natural strategy for both passing and preventing stones. The NHS recommends aiming for up to 3 liters (about 100 ounces) of fluid per day. The goal is simple: keep your urine pale or clear. When urine is concentrated, the minerals that form stones reach higher saturation levels. Diluted urine makes it harder for crystals to grow and easier for small fragments to wash through.
Water is the best choice. Spread your intake throughout the day rather than drinking large amounts at once, and keep a glass of water by your bed so you stay hydrated overnight, when urine tends to become most concentrated.
How Citrate Works Against Stones
Citrate is one of your body’s built-in defenses against kidney stones. It works in two ways: it binds to calcium in urine, forming a soluble complex that keeps calcium from joining with oxalate to create crystals. It also directly inhibits crystal formation, growth, and clumping. The University of Chicago Kidney Stone Program describes citrate as a dual-action inhibitor because of these combined effects.
You can increase your citrate levels through diet. Lemon juice and other citrus fruits are naturally rich in citric acid. A common approach is squeezing fresh lemon juice into your water throughout the day. This won’t dissolve an existing calcium stone, but it can slow growth and help prevent new ones. For people with low urinary citrate levels, doctors sometimes prescribe potassium citrate supplements, which are far more concentrated than what you’d get from food.
Uric Acid Stones Can Actually Dissolve
Uric acid stones are unique. They’re the only common stone type that can be chemically dissolved without a procedure. The key is raising urinary pH to between 6.5 and 7.0, which creates conditions where uric acid crystals can’t hold together.
A systematic review in the Société Internationale d’Urologie Journal confirmed that oral alkalinization therapy, typically using potassium citrate or sodium bicarbonate, successfully dissolves uric acid stones. This is a medically supervised process. Your doctor will have you test your urine pH regularly and adjust the dose to stay in the target range. It’s not a home remedy you should attempt on your own, because pushing pH too high can create conditions for a different type of stone (calcium phosphate).
If you don’t know what type of stone you have, this distinction matters. Roughly 5 to 10% of kidney stones are uric acid. Calcium oxalate stones, which make up the majority, cannot be dissolved through pH changes or any oral therapy currently available.
Reduce Sodium to Lower Calcium in Urine
High salt intake directly increases the amount of calcium your kidneys excrete, which raises your risk of calcium-based stones. In a controlled study published in The Journal of Urology, when subjects went from a low-sodium diet to a high-sodium one, their urinary calcium jumped by about 44%. At the same time, their citrate levels dropped, removing one of the body’s natural stone-fighting compounds. Salt essentially creates a double hit: more stone-building material and less stone-preventing material.
Most guidelines recommend keeping sodium under 2,300 mg per day. Processed foods, restaurant meals, canned soups, and deli meats are the biggest sources. Cutting back on these can meaningfully change your urine chemistry within days.
The Calcium Paradox
It seems logical that eating less calcium would prevent calcium stones, but the opposite is true. Women in the highest fifth of dietary calcium intake had a 65% lower risk of kidney stones compared to women in the lowest fifth, according to data in The American Journal of Clinical Nutrition. The reason: calcium from food binds to oxalate in your gut before it ever reaches the kidneys, preventing oxalate from being absorbed into the bloodstream and ending up in urine.
Calcium supplements, on the other hand, increased stone risk by about 17 to 20%. The difference is timing and context. Food-based calcium mixes with oxalate during digestion. Supplements taken between meals don’t have that opportunity and instead raise blood calcium levels, which the kidneys then filter out.
The practical takeaway: get your calcium from dairy, fortified foods, or other dietary sources rather than pills. And don’t cut calcium in an attempt to prevent stones, as that actually increases oxalate absorption and makes things worse.
Foods to Limit if You Have Calcium Oxalate Stones
Since most kidney stones contain calcium oxalate, reducing dietary oxalate can help. The National Institute of Diabetes and Digestive and Kidney Diseases identifies these as the highest-oxalate foods to watch:
- Spinach, which contains more oxalate per serving than almost any other food
- Rhubarb
- Nuts and nut products
- Peanuts (technically a legume, but very high in oxalate)
- Wheat bran
You don’t need to eliminate these entirely, but if you’re a regular stone former, cutting back on the biggest offenders and pairing high-oxalate foods with calcium-rich foods at the same meal can reduce the oxalate that reaches your kidneys.
Herbal Remedies: What the Evidence Shows
Chanca piedra (Phyllanthus niruri) is the most studied herbal supplement for kidney stones. A randomized trial published in The Journal of Urology tested it in 150 patients who had already undergone shock wave treatment to break up their stones. Those who took chanca piedra extract afterward had a stone-free rate of 93.5% at six months, compared to 83.3% in the control group. The strongest effect was for stones in the lower part of the kidney, where the stone-free rate jumped from 70.8% to 93.7%. No side effects were recorded.
The important caveat: this study used chanca piedra after a medical procedure, not as a standalone treatment. The herb appeared to help clear fragments and possibly prevent re-crystallization, not break up intact stones. There’s no clinical evidence that chanca piedra alone can dissolve or fragment a stone sitting in your kidney or ureter.
Apple cider vinegar is widely promoted online, but the evidence is thin. A 2017 epidemiological study found an association between fermented vinegar consumption and lower stone risk, and a 2014 animal study suggested some kidney-protective antioxidant effects. No human clinical trial has demonstrated that apple cider vinegar dissolves kidney stones. The acetic acid concentration in dietary vinegar is low, and there’s no established mechanism by which it would break apart a calcium oxalate crystal in the urinary tract.
What Helps a Stone Pass Faster
While you’re waiting for a small stone to pass, a few strategies can help move things along. Staying very well hydrated increases urine flow and helps push the stone through. Physical activity, even just regular walking, may help the stone shift through the ureter. Some doctors prescribe an alpha-blocker medication that relaxes the smooth muscle in the ureter, making it easier for stones (especially those 5 to 10 mm) to pass.
Pain during stone passage comes in waves as the ureter contracts around the stone. Over-the-counter anti-inflammatory medications are typically the first choice for pain relief during this process. A heating pad on your back or side can also help with the discomfort. Most stones that are going to pass naturally do so within a few days to six weeks, depending on size and location. If pain becomes severe, you develop a fever, or you can’t keep fluids down, that changes the situation from watchful waiting to something that needs urgent evaluation.