How Long Does It Take to Pass a Kidney Stone?

How long does it take to pass a kidney stone? It depends mostly on size. Smaller stones often pass within one to two weeks, while larger stones can take several weeks and sometimes require treatment to move things along. If you have been trying to pass a stone for more than four to six weeks, it is time to call us.

Stones smaller than 4mm pass on their own in the large majority of cases, often within a couple of weeks. Stones in the 4 to 6mm range still have a good chance of passing without surgery, but it can take up to six weeks and some patients benefit from medication to help. Stones larger than 6mm are far less likely to pass on their own and usually need a procedure to remove or break them up.

Size is not the only factor. A stone sitting near the bladder end of the ureter tends to pass more easily than one still close to the kidney. This is one of the reasons imaging is useful early on: it tells us not just how big the stone is, but where it is and how far it still has to travel.

Staying well hydrated is the simplest thing you can do while a stone is passing. We may also prescribe medication that relaxes the ureter to make passage more comfortable and more likely. Pain control matters too, since a stone that is actively passing can be genuinely painful, and there is no reason to tough it out unnecessarily.

Watching and waiting is reasonable for many patients, but not indefinitely, and not through every symptom. If pain becomes unmanageable, if you develop a fever, or if you are unable to urinate, that is no longer a wait-and-see situation. Call us or seek emergency care right away.