Most kidney stones smaller than 5 mm will pass on their own with enough fluids and pain control. Larger stones may need medication to help them along, and stones bigger than about 2 cm typically require a procedure. What you should do depends on the size of your stone, where it is, and how severe your symptoms are.
Know When You Need Emergency Care
Before trying to manage a stone at home, rule out a situation that needs immediate medical attention. Get to an emergency room or urgent care if you experience pain so severe you can’t sit still or find a comfortable position, pain with fever and chills (which can signal an infection behind the blockage), inability to urinate, or uncontrollable nausea and vomiting. Blood in your urine is common with kidney stones, but it also warrants a same-day medical evaluation if you haven’t already been diagnosed.
Managing Pain While a Stone Passes
Anti-inflammatory pain relievers like ibuprofen and naproxen are the first line of defense, not just because they reduce pain but because they decrease the swelling in the ureter that makes passage harder. In emergency settings, prescription-strength anti-inflammatories work as fast as opioids and are often just as effective. Intravenous acetaminophen has also shown pain relief equal to, and sometimes better than, morphine in studies of kidney stone pain.
For at-home management, over-the-counter ibuprofen or naproxen taken on a regular schedule (not just when the pain spikes) is generally more effective than waiting for pain to become severe. A heating pad on your lower back or side can also help relax the muscles around the ureter.
How Likely Your Stone Is to Pass on Its Own
Stone size is the biggest factor, but location matters just as much. A stone that has already traveled to the lower section of the ureter (closest to the bladder) has much better odds than one sitting higher up near the kidney. Here’s how the numbers break down:
- Small stones (under 5 mm) in the lower ureter: about 74% pass without intervention
- 5 mm stones in the lower ureter: about 45% pass
- Larger stones (over 5 mm) in the lower ureter: about 25% pass
- Small stones in the upper ureter: about 53% pass
- Larger stones in the upper ureter: essentially 0% pass on their own
Your doctor can tell you the size and location from a CT scan, which gives you a realistic sense of whether watchful waiting is a reasonable strategy or you’re heading toward a procedure.
Medications That Help Stones Pass
For stones between 5 and 10 mm that are in the lower ureter, your doctor may prescribe tamsulosin, a medication that relaxes the smooth muscle lining the ureter to give the stone more room to move. In clinical trials, 83% of patients with these mid-sized stones passed them with tamsulosin, compared to 61% without it. The effect is modest for very small stones, since those tend to pass regardless.
Uric acid stones are a special case. They’re the only type of kidney stone that can actually be dissolved with medication rather than just waiting for them to pass. The treatment involves taking an alkalizing agent (typically potassium citrate) to raise your urine pH to between 6.5 and 7.0, which creates conditions where the uric acid crystals break down. Your doctor will have you monitor your urine pH at home and adjust the dose accordingly. This approach can dissolve stones over weeks to months, potentially avoiding a procedure altogether.
When You Need a Procedure
If a stone is too large to pass, is causing an infection, or hasn’t budged after a reasonable waiting period, there are three main procedures your doctor will consider. The choice depends on stone size and where it’s lodged.
Shock Wave Lithotripsy
This noninvasive option uses focused sound waves from outside your body to break the stone into smaller fragments that you then pass naturally. It works well for stones up to about 1 cm and is typically done as an outpatient procedure. For stones in the lower part of the kidney between 1 and 2 cm, its success rate drops to around 58%, making it a less reliable choice for larger stones in that location.
Ureteroscopy
A thin scope is passed through your urethra and bladder up into the ureter, where a laser breaks the stone apart. There’s no incision. For stones 1 to 2 cm in the lower part of the kidney, ureteroscopy has an 81% success rate, significantly better than shock wave therapy. For stones under 1 cm, the two approaches are considered equally effective, so the choice often comes down to patient preference and stone location. When treating lower-pole stones (the bottom of the kidney), surgeons will often reposition the stone to a more accessible spot before breaking it up, which improves results.
Percutaneous Nephrolithotomy
For large stones over 2 cm, a small incision in the back provides direct access to the kidney, and the stone is broken up and removed through a scope. This is more invasive than the other options but has the highest success rate for big stones. A newer “mini” version of this procedure uses smaller instruments and is associated with fewer complications, less pain, and shorter hospital stays while achieving comparable stone clearance.
Hydration Is the Single Best Prevention
If you’ve had one kidney stone, your chance of having another within 5 to 10 years is roughly 50%. The most powerful thing you can do to prevent recurrence is drink enough fluid to produce at least 2.5 liters of urine per day. That typically means drinking about 3 liters (roughly 100 ounces) of fluid daily, though you’ll need more if you’re active or live in a hot climate.
The numbers are striking: drinking more than 2 liters of water daily is associated with a 61% reduction in stone risk compared to lower intakes. At 3.1 liters per day, stone risk drops by 26% compared to people drinking just 1.5 liters. Water is the best choice. Spread your intake throughout the day and keep drinking into the evening, since urine becomes most concentrated overnight.
Dietary Changes That Reduce Stone Risk
Most kidney stones are made of calcium oxalate, and the dietary adjustments that matter most may be counterintuitive.
Don’t cut calcium. Despite the name “calcium stones,” reducing dietary calcium actually increases your risk. Calcium binds to oxalate in your digestive tract, preventing it from being absorbed and reaching your kidneys. The key is getting calcium from food (dairy, fortified foods) rather than supplements, and eating it at the same meals where you consume higher-oxalate foods like spinach, nuts, and chocolate.
Cut sodium to under 2,300 mg per day. That’s about one teaspoon of table salt. Excess sodium causes your kidneys to excrete more calcium into the urine, directly feeding stone formation. This guideline applies to both calcium oxalate and calcium phosphate stone formers, even if you’re already taking preventive medication. Since most sodium comes from processed and restaurant foods rather than the salt shaker, reading labels is the most effective strategy.
Moderate animal protein. Red meat, poultry, eggs, and seafood increase uric acid production and lower your urine’s citrate levels. Citrate is a natural stone inhibitor, so less of it means higher risk. You don’t need to go vegetarian, but keeping portions moderate and mixing in plant-based protein sources helps.
Potassium Citrate for Long-Term Prevention
If dietary changes and hydration aren’t enough, your doctor may prescribe potassium citrate as a daily supplement. It works by making your urine less acidic, which inhibits the formation of both calcium-based and uric acid stones. Citrate also directly binds to calcium in urine, preventing it from crystallizing.
For uric acid stone formers specifically, maintaining a urine pH between 6.5 and 7.0 with potassium citrate not only prevents new stones but can dissolve existing ones. People who form calcium oxalate stones benefit too, since higher citrate levels in the urine act as a chemical shield against crystal growth. Your doctor will check your urine composition with a 24-hour urine collection to determine whether citrate supplementation is appropriate and to tailor the dose.