Men get urinary tract infections when bacteria enter the urethra and travel upward into the bladder, prostate, or kidneys. While UTIs are far less common in men than women, they do happen, and certain risk factors make some men significantly more vulnerable. The longer male urethra provides more of a barrier against infection, but it’s not foolproof.
How Bacteria Enter the Male Urinary Tract
Nearly all male UTIs start the same way: bacteria climb up through the urethra in what’s called an ascending infection. E. coli, the gut bacterium responsible for most UTIs in women, causes about 25% of male cases. The rest are caused by a wider variety of bacteria, including Proteus, Klebsiella, and Pseudomonas species. This is one key difference from female UTIs, where E. coli dominates.
Once bacteria reach the bladder, they can keep spreading. They can migrate through the prostatic ducts into the prostate gland, carried by small amounts of urine that flow backward. From there, infected urine can travel further up through the vas deferens and into the epididymis (the coiled tube behind each testicle). If bacteria reach the kidneys, the infection becomes much more serious.
The Prostate Connection
The prostate gland wraps around the urethra just below the bladder, and when it enlarges, it squeezes the urethra and blocks normal urine flow. This is extremely common as men age. The problem isn’t just discomfort: when you can’t fully empty your bladder, the leftover urine becomes a breeding ground for bacteria. That stagnant urine is one of the most common reasons older men develop UTIs.
The relationship goes both directions. An enlarged prostate raises UTI risk, and a UTI can spread into the prostate itself, causing prostatitis. Acute bacterial prostatitis can then lead to further complications, including a pus-filled abscess in the prostate, infection of the epididymis, bloodstream infection, or infection spreading to the pelvic bones or lower spine.
Circumcision Status
Being uncircumcised is one of the strongest risk factors for male UTIs across the entire lifespan. A large meta-analysis found that uncircumcised males have a 3.7 times higher lifetime risk of UTI compared to circumcised males. The numbers are striking: roughly 32% of uncircumcised males will experience at least one UTI in their lifetime, compared to about 9% of circumcised males.
The risk is highest in infancy, where uncircumcised boys face a nearly 10-fold increased risk. It drops to about 6.6 times higher during childhood and adolescence, then settles around 3.4 times higher in adulthood. The foreskin can harbor bacteria near the urethral opening, giving them a shorter path to entry.
Sexual Activity
Sex can introduce bacteria into the urethra. Anal intercourse carries a particularly elevated risk because it exposes the urethra to the types of gut bacteria (like E. coli) most likely to cause infection. This is distinct from sexually transmitted infections, though the symptoms can overlap. STI-related urethritis in men is most commonly caused by gonorrhea, while chlamydia accounts for up to 50% of non-gonococcal cases. These aren’t technically UTIs, but they affect the same anatomy and can feel similar.
In men under 35, sexually transmitted bacteria are the most common cause of epididymitis. In older men, the same condition is more often caused by ordinary urinary bacteria that have spread from a bladder or prostate infection.
Catheters and Hospital Settings
Urinary catheters are a major source of UTIs for men, especially during hospital stays. About 75% of all UTIs acquired in hospitals are associated with catheter use, and 15 to 25% of hospitalized patients have a catheter at some point. The single biggest risk factor is how long the catheter stays in place. Every day it remains increases the chance of bacteria traveling along the tube into the bladder.
If you or a family member has a catheter, keep the urine collection bag below the level of the bladder at all times. Don’t tug, pull, or kink the tubing. Clean your hands before and after touching any part of the catheter. Most importantly, ask the care team regularly whether the catheter is still necessary.
Other Medical Risk Factors
Diabetes changes the body’s immune defenses in ways that make urinary infections more likely. High blood sugar can impair white blood cell function and promote bacterial growth in the urinary tract.
Kidney stones or any structural blockage in the urinary tract creates the same stagnant-urine problem as an enlarged prostate. Urine that can’t flow freely gives bacteria time to multiply. If the underlying blockage isn’t corrected, recurring infections can eventually damage the kidneys.
What Male UTI Symptoms Feel Like
Symptoms depend on where the infection has settled. A bladder infection typically causes frequent, painful urination, pressure in the lower belly, and sometimes blood in the urine (which can look pink, red, or cola-colored). You may feel a persistent, strong urge to urinate but only pass small amounts each time.
If the infection is limited to the urethra, burning during urination and discharge are the main signs. A kidney infection is more serious and feels different: pain in the back or side, high fever, shaking chills, nausea, and vomiting. Kidney infections need prompt treatment to prevent lasting damage.
How Male UTIs Are Diagnosed
Diagnosing a UTI in men involves a urine culture, but the threshold for a positive result is actually lower than for women. Most guidelines consider a bacterial count of 1,000 to 10,000 colony-forming units per milliliter significant in men, compared to 100,000 for women at average risk. This lower bar exists because any meaningful bacterial growth in a male urine sample is more likely to represent a true infection rather than contamination.
Because male UTIs are less common and more likely to signal an underlying problem, doctors will often investigate further, looking for prostate enlargement, kidney stones, or structural abnormalities that explain why the infection happened in the first place.
What Happens if a Male UTI Goes Untreated
A bladder infection that isn’t treated can spread to the prostate, causing acute bacterial prostatitis, which brings severe pelvic pain, difficulty urinating, fever, and chills. From the prostate, infection can reach the epididymis or enter the bloodstream, a condition called bacteremia that requires emergency treatment. In rare cases, infection can spread to the bones of the pelvis or lower spine.
UTIs caused by an underlying obstruction, whether from an enlarged prostate or a kidney stone, are especially dangerous if left alone. The combination of ongoing blockage and active infection can lead to progressive kidney damage that may not be fully reversible.