Kidney Stone Treatment
Treatment of kidney and urinary tract stones based on their size, location, symptoms and likelihood of passing naturally
What is kidney stone treatment?
A kidney stone is a crystal that has grown out of solution in the urine. Calcium oxalate is the commonest kind, followed by uric acid, and each forms when the substance is concentrated enough and there is too little water and citrate to hold it dissolved.
Stones grow quietly inside the collecting system of the kidney. Trouble begins when one moves, because the drainage narrows as it leaves the kidney and a stone that fits comfortably in the kidney will not always fit the tube below it.
Size and position decide almost everything that follows. A four millimetre stone low in the ureter usually clears on its own; the same stone in the lower pole of the kidney may sit there for years; a two centimetre stone will not clear whatever you drink. Your urologist measures it on a CT and works from that number.
What you might notice
- Sharp pain in the back or side
- Blood in urine
- Fever alongside the back or side pain
- Nausea coming in waves with the pain
- Burning when passing urine
How it is diagnosed
The test that settles it is a low dose CT of the kidneys, ureters and bladder, which finds stones of almost any composition and gives their size and exact position. Ultrasound is used first in pregnancy and in children, and it shows a swollen kidney well even when it misses the stone itself.
Urine is dipped and cultured, because infection sitting behind a blockage changes the urgency of everything. Blood tests cover kidney function and calcium.
If you have formed more than one stone, expect a metabolic screen on a twenty-four hour urine collection, and analysis of the stone itself if it is retrieved. That is what explains why you are forming them and what can be changed.
Recovery
Passing a stone naturally takes days to weeks. You are given medication that relaxes the lower ureter, something to take alongside it, and instructions to strain your urine and bring in whatever comes out.
After treatment along the natural passage most people go home the same day and are back at desk work within two or three days. A tube left inside to keep the kidney draining is the part people find hardest, and it can leave the bladder feeling unsettled until it is taken out a week or two later. Where a track has been made through the flank, expect one to three nights in hospital and two to three weeks before heavy work.
A scan at six to twelve weeks confirms the kidney is clear and draining, because fragments left behind are the seed of the next stone.
If it is left untreated
A stone sitting in the kidney and blocking nothing can be watched, and small lower pole stones are often followed for years with an occasional scan.
A stone blocking the ureter is a different matter. Pressure backs up into the kidney and, if it is not relieved, that kidney loses function over weeks to months. It can happen silently once the first episode has settled, so waiting is supervised with a repeat scan and not left open-ended.
A blockage with infection behind it is an emergency. It can become sepsis within hours and the kidney has to be drained the same day. Stones also recur: around half of people form another within ten years if nothing changes about fluid, salt and diet.
Questions about kidney stone treatment
Will my stone pass on its own?
It depends almost entirely on size and where it is. Stones of five millimetres or less pass in most people, usually within four weeks, and you may be given a tablet that relaxes the lower ureter to help that along. Between five and eight millimetres the odds fall sharply, and above eight millimetres very few clear without help. A stone still sitting in the kidney is not going anywhere at all on its own, whatever its size, so the decision there is between shock wave lithotripsy, RIRS and a percutaneous approach depending on how big and how hard it is.
Why has a stent been left inside and when does it come out?
A DJ stent keeps the kidney draining while the ureter, which has been instrumented and is swollen, recovers. It runs from the kidney to the bladder and you cannot see or feel the ends of it, though many people are aware of it when they pass urine or exert themselves. It usually stays one to three weeks and is removed at a short outpatient visit with a fine telescope under local anaesthetic, which takes a few minutes. Tell your urologist if it is troubling you, because the timing has some flexibility, and never let one be forgotten, since a stent left for many months encrusts and becomes difficult to remove.
What stops me forming another one?
Fluid is the single biggest factor. The target is enough water through the day to produce two and a half litres of urine, spread out instead of taken all at once. Cutting salt lowers the calcium in your urine, and a normal calcium intake is protective, so dairy is not restricted unless you are told otherwise. Oxalate-heavy foods matter mainly in people who form calcium oxalate stones repeatedly. If you have had two or more stones, a twenty-four hour urine collection and analysis of the stone itself will show which of these applies to you, and sometimes a medication such as potassium citrate is added.
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Day CareTalk to a care coordinator about kidney stone treatment
Leave a number and a care coordinator calls you back with what the treatment involves and which hospital it would be at. They book a consult only if you want one