Most kidney stones smaller than 5 millimeters will pass on their own with enough fluids and pain management. For stones between 5 and 10 mm, medications that relax the ureter can improve your chances of passing them without a procedure. Larger stones, or those causing serious symptoms, typically need one of several minimally invasive treatments to break them up or remove them.
Managing Pain While You Wait
Kidney stone pain can hit suddenly and intensely, often in waves as the stone moves through the ureter. Anti-inflammatory pain relievers like ibuprofen and naproxen are the recommended first-line treatment, according to European Association of Urology guidelines. They work by blocking the specific inflammatory chemicals that cause ureteral swelling and spasm, which means they treat the source of the pain rather than just masking it. Opioid painkillers are reserved as a backup when anti-inflammatories aren’t enough.
A heating pad on your back or side can help between doses. Staying active, even just walking, sometimes helps stones move along. If the pain becomes so severe you can’t sit still or find a comfortable position, or if you develop fever, chills, vomiting, or difficulty urinating, those are signs you need emergency care. A fever with a kidney stone can signal an infection behind the blockage, which is a urological emergency.
Helping Smaller Stones Pass
Drinking enough fluid to produce at least 2.5 liters of urine per day is the single most important thing you can do to help a stone pass. Water is ideal. The goal is to keep a steady, high volume of urine flowing through the ureter to push the stone along.
For stones larger than 5 mm that haven’t passed on their own, your doctor may prescribe a medication that relaxes the smooth muscle lining your ureter, making the tube wider and reducing the spasms that trap the stone. A large multicenter trial found this approach significantly improved expulsion rates for stones over 5 mm, though for stones 5 mm and smaller it didn’t make a meaningful difference compared to placebo. Those smaller stones tend to pass fine with fluids alone.
You may be asked to urinate through a strainer so the stone can be caught and sent for analysis. Knowing what type of stone you had is important for prevention.
Procedures for Larger Stones
When a stone is too large to pass, too painful to wait out, or blocking urine flow, there are three main procedures your urologist will consider. The choice depends mostly on stone size and location.
Shock Wave Lithotripsy
This noninvasive option uses focused sound waves from outside the body to break a stone into smaller fragments you can then pass naturally. It works best for stones under about 2 centimeters. The overall success rate is around 83%, and recovery is relatively quick since there are no incisions. You’ll typically pass sand-like fragments over the following days to weeks.
Ureteroscopy
A thin scope is passed through the bladder and up into the ureter to reach the stone directly. The surgeon can then break it apart with a laser and extract the pieces. This approach has a success rate of about 98%, making it more reliable than shock wave treatment, particularly for stones in the lower ureter. After the procedure, a small temporary tube called a stent is usually placed in the ureter to keep it open while swelling goes down. Most stents stay in for a few days to a few weeks. You can generally return to work within a day or two, though you should avoid lifting anything over 10 pounds for at least several days.
Percutaneous Nephrolithotomy
For stones larger than 2 centimeters, staghorn stones that fill multiple branches of the kidney, or cases where other procedures have failed, surgeons make a small incision in the back and use a scope to remove the stone directly from the kidney. This is the most involved option but is sometimes the only effective one for very large or complex stones.
Why Stone Type Matters
Not all kidney stones are the same, and knowing your stone type changes how you prevent the next one. About 80% of stones are calcium-based, mostly calcium oxalate. The rest are primarily uric acid stones, with rarer types like struvite and cystine stones making up a small percentage.
Uric acid stones form when urine is too acidic. The main treatment is raising urine pH to at least 6.0, usually with a potassium citrate supplement. In some cases, uric acid stones can actually be dissolved entirely without any procedure, simply by making the urine less acidic over time. Increasing the proportion of fruits and vegetables in your diet while reducing animal protein helps shift urine toward a more alkaline state.
Calcium oxalate stones involve a counterintuitive principle: you should not reduce your calcium intake. Lower calcium consumption actually increases stone risk because calcium in your gut binds to oxalate from food, preventing it from being absorbed into your bloodstream and ending up in your urine. The National Kidney Foundation recommends 1,000 to 1,200 mg of calcium per day, ideally from food sources eaten with meals. Two to three servings of dairy will cover it.
Preventing the Next Stone
Recurrence is the biggest long-term concern. Up to 40% of people who form one stone will form another within five years. The good news is that a few straightforward habits dramatically lower that risk.
Fluid intake is the foundation. The goal is producing more than 2.5 liters of urine daily, which for most people means drinking roughly 3 liters of fluid. The relationship between urine volume and stone risk is continuous: more is better, with no hard cutoff. Spreading your intake throughout the day matters more than drinking large amounts at once, and having a glass of water before bed helps prevent the overnight concentration of urine that promotes crystal formation.
Citrate is a natural stone inhibitor that binds to calcium in urine and prevents crystals from growing. Low citrate levels are found in 20 to 60% of stone formers. Drinking half a cup of lemon juice concentrate diluted in water each day, or the juice of two lemons, has been shown to increase urine citrate enough to likely reduce stone risk. For people with persistently low citrate on urine testing, a potassium citrate supplement is the standard recommendation.
Reducing sodium intake helps because excess salt increases the amount of calcium your kidneys excrete. Cutting back on animal protein, particularly red meat, lowers uric acid production and makes urine less acidic. High-oxalate foods like spinach, rhubarb, beets, and nuts don’t need to be eliminated entirely, but eating them alongside calcium-rich foods helps bind the oxalate before it reaches your kidneys.
If you’ve had more than one stone, a 24-hour urine collection test can identify your specific metabolic risk factors, whether that’s high oxalate, low citrate, high sodium, or abnormal pH. That test turns prevention from general advice into a targeted plan.