Ask us: Do I need to treat my 3mm stone?

In our “Ask a kidney stone doctor” section, we field questions from stone formers or their family members. Today’s question is about small non-symptomatic kidney stones. See other questions and answers or ask your own question here.


July 22, 2011

Question from Minnesota:

I have a 3mm to 4mm stone in my right kidney, which has been there since 2003.  It originally was very high up in the kidney, but moved to the lower part of the kidney in 2006. I just had another CT done, and it is still in the same place and the same size.  Because the stone is in the lower part of the kidney versus the higher part, is it less likely to pass, because it would have to go up to get into the ureter versus down? Because I’ve had this stone so long with no changes, what are the chances that it will just continue to sit there and never pass?  It has caused me no pain other than occasional blood in my urine. I was told by my doc that I could wait and watch the 3-4mm stone in my right kidney or proceed with ureteroscopy to remove it. It’s been sitting there since 2003 without giving me any discomfort. How painful is having a stent put in to promote healing after the ureteroscopy and is it really necessary?


Many patients are found with small stones and it can be confusing deciding on whether to proceed with treatment or to continue observing the stone(s). Several factors need to be considered to help make a decision:

1)    Size: Stones that are smaller than 5mm are more likely to be able to pass successfully without requiring surgery. When a stone is larger (>6mm) and unlikely to pass successfully, it may make more sense to intervene. In your case, the stone is small and if it were to start moving down the ureter, it would have a good chance of passing spontaneously. However, successful passage does not mean non-painful passage as even small stones can cause significant discomfort when they move down the ureter. Because of this, patients who have already experienced a stone episode in the past are usually more motivated to have an early intervention so that they can avoid another stone passage episode.

2)    Stability: Stones that are growing are more likely to lead to problems while stones that stay the same size are less likely to become symptomatic. As your stone is stable over 8 years, one could argue to continue to watch it.

3)    Location: Stones that are not obstructing, like yours, are generally asymptomatic. Stones that are floating in the renal pelvis or ureter are more likely to cause obstruction and more likely to require intervention. Stone fragments in the lower pole are generally felt to be less likely to pass. However, in addition to whether the stone is in the upper pole, middle-pole, or lower pole of the kidney, researchers have focused on the “calyceal anatomy” which can be though of as the length of the “tunnel” and the angle of the “tunnel” that the stone would have to travel to end up in the center part of the kidney where it could start making its way down the ureter.

4)    Symptoms: Stones that cause symptoms such as pain, recurrent infections, or significant bleeding would be more likely to require intervention than stones that are causing minimal symptoms.

5)    Other things to consider: Certain individuals will be advised to have their stone treated even if it is small and asymptomatic. This includes pilots, who would put themselves and their passengers at risk if they were to experience a stone passage episode while flying, and travelers to remote locations, where modern medical facilities may not be available if they were to suffer a stone attack.

The short answer as to how likely your stone is to remain there without causing problems is 80% over the next 3-10 years. Another way of looking at this is that 20%, or 1 out of 5 patients in your situation will experience a stone passage episode over the next 3-10 years while 4 out of 5 will do fine without experiencing problems. Here’s the long answer: Based on a study of 5,047 adults who underwent CT colonography screening, asymptomatic stones, such as yours, are found in 8% of American adults. In that study, the average stone size was 3mm. Over 10 years, 20.5% of patients with stones, or 1 out of 5, developed a symptomatic “stone episode” requiring intervention. Alternatively, 4 out of 5 patients did fine without experiencing a stone episode. This rate of 20% of small stones requiring treatment when observed is remarkably consistent with multiple other studies where patients with small stones were observed.

Finally, as to your question about ureteral stents, stents are often required after ureteroscopy surgery because of the ureter’s tendency to swell temporarily and become blocked after this type of surgery. This swelling can cause pain similar to a stone episode. We’ve found that this is more likely to occur in patients who have not had prior ureteroscopy surgery. Note though that this is a “surgeon’s preference” as some urologists will be more likely to perform ureteroscopy without leaving a stent. Stent pain can be mild or can be very uncomfortable. While some patients do not even realize a stent is there, most can’t wait to have them removed and some patients will say that the stent was worse than their stone. One way to potentially avoid a stent is to consider shockwave lithotripsy (ESWL) if the stone is easily visible on a plain x-ray.

About Dr. Mike Nguyen

Mike M Nguyen, MD, MPH, is a urologist and an Associate Professor of Clinical Urology at the Keck School of Medicine of USC in Los Angeles, CA. He specializes in the treatment of kidney stones with both surgery and dietary prevention and the in the treatment of kidney and prostate cancer using the latest robotic surgical approaches. He sees patients at clinics located in Los Angeles, Pasadena, and La Canada, CA. He is the founder of the website.
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52 Responses to Ask us: Do I need to treat my 3mm stone?

  1. Zi says:

    Hi, I have a pain in the left flank. Cat scan from last year showed a 1 mm stone in the middle of the kidney and this year can scan showed 1 mm stone in the lower part of the kidney. I have pain every night/morning and lately pain until lunch time. My doctor told me the pain is not from the stone and I should visit nephrologist. I will go to a specialist but wonder until I get there what can the doctor do since the stone is very small. My blood results are good except createnine bun ration which is a little high and also have a little blood in the urine.Please let me know if 1 mm stone can cause a pain?

  2. Rup lal says:

    i have peri pelvic cyst in right kedney of 52mm*39mm in mid polar region. no pain and no any symtoms but i am worried that it is very big infuture symtoms must arise please tell me what can i do i am 61 years

  3. Joy Renn Tan says:

    A blessed day Sir.
    I would like to ask if what is the meaning of this diagnosis of my mother: Non – Obstructing inferior calyceal calculus , Left.

    Also, there is 0.82 cm shadowing echogenic focus seen in the inferior pole of the her left kidney.

    It is almost a year when the first aching of her left side (back, above the abdomen).
    She always feel something hot on that part.

    I hope for your reply Sir.
    God bless po.
    Thank you po.

  4. Mukesh kumar says:

    I had URS sergery 4 days before in left ureter to remove 9 mm calculus. But doctors coluld remove only half of it by URS Sergery. Exact Calculus location was upper left ureter but now residual 4.5 mm part is there in inter pole calyx as per latest sonography .they have placed a stent also in ureter. Please suggest what can be done to get rid of it.

  5. Mubaiwa says:

    I have had a sonogram and have a 3.2×2.7 cm calyceal cyst mass in my right kidney. What should I do? go for surgery, do nothing. I have no pain.

  6. mohit says:

    sir my mother have 8mm kidney stone since 10 days.

  7. rajeev rana says:

    Sir I have 5 mm calculus is on meadle stomach an how to treat sir plzz suggest me.

  8. md shahnawaz alam says:

    hello sir
    u have 03mm×03mm calcification or calculus is seen in middle calyx of left kidney please saggest me what i have to do

  9. Farooq Ahmad says:

    i have a tiny rt.renal calculus in uppers calyx.i have little pain in rt.side of abdomin.what should i do.

  10. mohammed thasneem says:

    sir I have a pain with both kidneys.since two month.consult with my docter he says 3 to 4 mm size stone I got medicine but my mined not set I need some solution pls…..

  11. venkat says:

    hai sir, i have right kidney pain , from few days , both kidneys are pain and i cant able to walk and also back bone pain from few days , i consult doctor , he told me go for scanning , i found a 3.5mm stone in left kidney at interpoler calyx, he me medicines and i am having antibitic tabs , but i had a lot of pain in right side kidney, i cant sleep, walk and walk , its pain like pin pussing.
    so sir i am requesting you to give me a valuable suggestion

  12. Uttara says:

    I have 3mm calculus In my left kidney calyx and I’m bledding since 10 days.what should I do?

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