Treating the stone is the easy part. Preventing the next one is where the value is.
What they are
Hard masses formed when minerals in the urine crystallize and clump together. Most are calcium based. Trouble starts when a stone moves into the ureter and blocks it: urine backs up and stretches the system behind it, and that stretch produces some of the most severe pain a person can experience. Stones recur often enough that prevention deserves far more attention than it usually gets.
Treatment
Small stones often pass on their own with hydration and time. Larger ones are treated with ureteroscopy, where a small flexible scope goes up and a laser breaks the stone, with no incision. Shock wave lithotripsy breaks stones from outside the body and still suits the right stone in the right place. Very large stones are removed through a small opening in the back.
Whether a stone will pass mostly comes down to how big it is and where it sits. If you have a report in front of you with a number on it, Kidney Stone Size: What Passes on Its Own and What Doesn’t walks through what that number means, the odds, how long it takes, and the one symptom that means go to the emergency room tonight.
Prevention is the part that gets skipped
A full stone workup has three parts. A 24-hour urine collection measures what is actually in your urine and shows which abnormalities are driving your stones, because often it is more than one. Blood work looks for the specific contributors, calcium, uric acid, kidney function and the hormones that regulate them. Stone analysis tells us what the stone was made of. That combination is the stone workup, and most stone formers never get it, which is a missed opportunity to stop the next stone.
Depending on what it shows, prevention may involve fluid targets, dietary changes that are often the opposite of what people assume, and medication. Uric acid stones can sometimes be dissolved outright by making the urine less acidic. Calcium stones cannot.
Stone prevention is an active part of my practice
If you have made more than one stone, or made a first one and would rather not repeat it, the workup is worth doing properly.