Kidney stones can be broken up through several methods depending on their size, location, and chemical composition. Small stones (under 5-6 mm) often pass on their own with extra fluids and pain management, while larger stones may need shock wave therapy, laser procedures, or surgery. One specific type, uric acid stones, can actually be dissolved with oral medication alone.
Stones That Pass on Their Own
Most kidney stones smaller than about 5 to 6 millimeters will pass through the urinary tract without a procedure. The process is painful but manageable. Your body doesn’t technically “break up” these stones; it pushes them out whole. Drinking enough fluid to produce at least 2 to 2.5 liters of urine per day helps keep things moving.
An alpha-blocker medication (commonly tamsulosin) can speed the process significantly. This drug relaxes the smooth muscle in the ureter, the narrow tube connecting your kidney to your bladder. In one clinical trial, the stone passage rate jumped from 71% with fluids alone to over 90% with the addition of tamsulosin, and the average time to pass the stone dropped from about 14 days to under 10. This approach is called medical expulsive therapy, and it’s typically the first thing a urologist will try for smaller stones stuck in the lower ureter.
Shock Wave Lithotripsy (ESWL)
For stones that are too large to pass but not massive, shock wave lithotripsy is the least invasive procedural option. You lie on a table while a machine sends focused shock waves through your skin and into the stone. The waves pulverize it into sand-like fragments small enough to pass naturally in your urine over the following days or weeks. No incisions are involved, and it’s usually done under sedation or light anesthesia.
Success rates depend heavily on stone size and location. Stones smaller than 10 mm have an 84% success rate, while stones larger than 10 mm drop to about 64%. Location matters too: stones in the upper part of the kidney respond very well (up to 100% clearance in some studies), while stones lodged in the lower pole of the kidney are harder to treat this way because gravity works against fragment clearance. A single session can deliver up to 4,000 shock waves over roughly 45 minutes to an hour.
Recovery is relatively quick. You may see blood in your urine for a day or two and feel bruising where the waves entered. Some people need a second session if the stone doesn’t fully fragment the first time.
Laser Lithotripsy Through a Scope
When shock waves aren’t ideal, or the stone is in a tricky location, urologists often use ureteroscopy with laser lithotripsy. A thin, flexible scope is passed through your urethra and bladder up into the ureter or kidney. Once the scope reaches the stone, a laser fiber (typically a holmium laser) fires directly at it, breaking it into tiny pieces or even turning it to dust.
This approach works well for stones in the ureter and for medium-sized kidney stones. Because the scope goes directly to the stone, location matters less than it does with shock waves. The fragments are either extracted with a small basket or left as fine dust that washes out with urine. A temporary stent (a thin tube inside the ureter) is often placed afterward to keep the ureter open while swelling subsides, and it’s removed in the office a week or two later. Most people go home the same day.
Surgery for Large or Complex Stones
Stones larger than about 1.5 to 2 centimeters, or stones that fill multiple branches of the kidney (called staghorn stones), generally require percutaneous nephrolithotomy, or PCNL. This is the gold standard for large, complex kidney stones. A surgeon makes a small incision in your back and creates a direct channel into the kidney, then uses a combination of ultrasonic, pneumatic, or laser energy to break the stone apart and suction out the fragments.
PCNL is highly effective. In a recent audit of outcomes for stones averaging 2.5 cm, single-session clearance reached 83%. Hospital stays are typically one to three days, though complications like persistent urine leakage occasionally extend that. Despite being more invasive than the other options, PCNL remains the most reliable way to completely clear large stones in one procedure.
Dissolving Uric Acid Stones With Medication
Uric acid stones are unique because they can be dissolved without any procedure at all. These stones form when urine is too acidic (pH below 6.0), and the fix is straightforward: raise the urine pH. Potassium citrate tablets or sodium bicarbonate are taken orally to bring urine pH into the 6.5 to 7.2 range, at which point uric acid crystals gradually dissolve.
This process, called oral chemolysis, works well but takes patience. It can take weeks to fully dissolve a stone, and you’ll need to monitor your urine pH regularly with test strips. The key factor is knowing the stone type. Uric acid stones don’t show up well on standard X-rays (they’re radiolucent), so a CT scan is typically used for diagnosis. If your stone is calcium-based, which is the most common type, dissolution therapy won’t work.
Managing Pain While a Stone Passes
The pain from a kidney stone, called renal colic, happens because the stone blocks urine flow. That blockage increases pressure in the kidney and triggers a cascade of inflammation and ureteral spasm. Anti-inflammatory painkillers (NSAIDs like ibuprofen or ketorolac) are actually more effective for this type of pain than opioids. A pooled analysis of six clinical trials found that NSAIDs produced greater pain reduction and that patients taking them were 25% less likely to need additional rescue painkillers. This is because NSAIDs directly reduce the prostaglandin release driving the pressure buildup, while opioids only mask the sensation.
Preventing New Stones From Forming
Once you’ve passed or had a stone treated, the recurrence rate is high, roughly 50% within 10 years, so prevention matters. The single most impactful step is drinking enough water to consistently produce pale, dilute urine.
For calcium oxalate stones, the most common type, a counterintuitive fact is worth knowing: eating adequate calcium actually helps prevent stones rather than causing them. Calcium binds to oxalate in your digestive tract before it ever reaches your kidneys, reducing the amount of oxalate that ends up in your urine. Cutting calcium intake, which many people instinctively do, can backfire. What you should limit are high-oxalate foods like spinach, rhubarb, nuts, peanuts, and wheat bran.
Lemon juice is a legitimate home strategy for boosting citrate in your urine, which inhibits stone crystal formation. As little as 4 ounces per day has been shown to significantly increase urine citrate levels without raising oxalate. You can dilute it in water throughout the day. For people who need stronger citrate supplementation, potassium citrate tablets are available by prescription.