Can Kidney Stones Cause UTIs? A Urologist Explains

How Can Kidney Stones Cause UTI?

A UTI (urinary tract infection) happens when bacteria, more usually E. coli, sneak into your urinary system and cause trouble. Most often, they stir things up in your bladder or prostate (in males), but sometimes, they head north to reach your kidneys.

Think of kidney stones as tiny clumps of minerals that build up in your kidneys when there’s too much “gunk” and not enough liquid in your urine. Some stones are so small you wouldn’t know they’re there, while others can give you the worst pain experience, which you'll never forget during your lifetime.

So, these two conditions are strongly connected, and we can say that yes, kidney stones can cause UT infection, and here's how:

How kidney stones open the door to infection

• When a kidney stone gets stuck, especially in the ureter (the tube between your kidney and bladder), it blocks the flow of urine. That urine backs up, creating a warm, «pacific» pool, which is basically an open invitation for bacteria to move in and multiply.
• Stones can also scrape and irritate the lining of your urinary tract, making it easier for bacteria to stick and start an infection.

Interestingly, the process can happen the other way. Some stones, like Struvite stones, actually form because of UTIs. It’s a vicious cycle.

Symptoms I Watch For

You might wonder: does a UTI caused by a kidney stone feel any different from a regular UTI?

Classic UTI symptoms include burning during urination, a frequent urge to go, and cloudy or foul-smelling urine. But when a kidney stone is also present, especially one that’s blocking the flow of urine, you’re more likely to experience additional symptoms, such as:

• Severe flank or back pain
• Nausea or vomiting
• Fever and chills, which may indicate the infection is spreading

So, a kidney stone plus a UTI can be very dangerous. If the blockage worsens, it can lead to kidney damage or worse, urosepsis, a life-threatening infection in the bloodstream. That’s why I don’t wait around, and I move to diagnostics.

How Do I Diagnose It?

The first step is testing your urine. A urinalysis looks for signs of infection, like white blood cells, bacteria, nitrites, or blood. A urine culture can identify the exact bacteria causing the UTI, which helps us choose the right antibiotic.

Blood test may be done to check for elevated white blood cell counts or signs that the infection has spread.

To confirm there’s a kidney stone and see where it’s located, I may use:

• CT scan (gold standard)
• Ultrasound (especially in pregnant patients or those avoiding radiation)
• X-ray (helpful for some types of stones)

These scans help check if the stone is blocking urine flow, a key factor in whether it's contributing to the infection.

The Game Plan: How to treat UTI from Kidney Stones?

Here’s how I handle it:

If the stone is small and not blocking anything, great. I’ll tell you to drink water like it’s your full-time job, hand you something for the pain, and let nature do the rest.

But if that stone is causing a blockage, and we’re dealing with an active infection on top of it? We’ve got to act fast.

In those cases, the top priority is to restore normal urine flow. Here’s how we do that:

• JJ ureteral stent: a small tube I insert from the bladder to the kidney, right past the stone. It lets urine drain properly while we plan the next steps.
• Nephrostomy tube: if the stent’s not an option, this tube goes directly through the back into the kidney to allow urine to drain outside the body.

These tools relieve the pressure and stop the infection from getting worse.

After restoring urine flow, I’ll send a urine sample to the lab and choose the antibiotic based on what bacteria we’re dealing with. It's targeted, it's precise, and it’s the quickest way to start turning things around.

Once the infection is under control and urine is flowing freely again, we can tackle the stone itself. Depending on its size, shape, and location, I’ll choose the best method to clear it:

• Shock wave lithotripsy (SWL): This treatment uses sound waves to break a kidney stone into tiny pieces, which you can then pass naturally when you urinate.
• Ureterorenoscopy: A tiny camera is inserted into the urinary tract to either break or remove the stone from the ureter and kidneys.
• Percutaneous Nephrolithotomy - In rare or more complex cases.

Staying Ahead of It…

Once we’ve treated it, I’ll give you some simple advice: keep drinking water, and also tips for preventing UTI. Hydration helps flush out minerals before they turn into stones and discourages bacteria from hanging around. If this is something you deal with often, we’ll dig deeper, look at your diet, lifestyle, or anything else that might be contributing.

I’d much rather help you prevent it than treat it again.