Urinary tract infections in men are uncommon compared to women, but when they do occur, there’s almost always an underlying reason. The male urethra is significantly longer than the female urethra, and the prostate gland produces secretions that kill bacteria, giving men a natural defense against infection. When a man develops a UTI, it typically signals that something is interfering with these protective mechanisms.
Why Men Get UTIs Less Often
The basic mechanics of male anatomy work against bacterial infection. The urethral opening sits at the tip of the penis, far from the bladder, so bacteria have a long path to travel before they can establish an infection. Prostatic fluid also has antibacterial properties that help clear organisms before they take hold. These two factors explain why UTIs in younger men are relatively rare and why most male UTIs cluster in older age groups, when prostate problems and other conditions begin to disrupt normal urinary flow.
Prostate Enlargement and Incomplete Emptying
The most significant risk factor for UTIs in older men is an enlarged prostate, a condition known as benign prostatic hyperplasia (BPH). As the prostate grows, it squeezes the urethra and makes it harder to fully empty the bladder. Urine that sits in the bladder becomes a breeding ground for bacteria. If you’re getting frequent UTIs and have symptoms of BPH like a weak stream, dribbling, or waking up multiple times at night to urinate, the infections are likely a downstream consequence of that incomplete emptying.
Chronic bacterial prostatitis, an ongoing low-grade infection of the prostate itself, is the most common cause of relapsing UTIs in men. The prostate can harbor bacteria that periodically re-seed the urinary tract. E. coli accounts for about 80% of these prostate infections.
Blockages and Structural Problems
Anything that physically obstructs urine flow raises UTI risk. Kidney stones or bladder stones can partially block the ureter or urethra, preventing bacteria from being flushed out during urination. Urethral strictures, which are areas of narrowing caused by scar tissue from prior surgery, injury, or radiation therapy, create the same problem. When urine can’t flow freely, bacteria have time to multiply. Obstruction also makes stone formation more likely, which creates a cycle: stones cause stagnation, stagnation causes infection, and infection can promote further stone growth.
Catheters and Hospital-Related Infections
Urinary catheters are one of the strongest risk factors for UTIs in men. A catheter provides a direct path for bacteria to enter the bladder, bypassing the natural defenses of the urethra. Essentially all patients with long-term catheters develop bacteria in their urine, and in up to 95% of cases, multiple bacterial species are involved simultaneously. Some of these organisms are particularly stubborn. Certain bacteria adhere to catheter surfaces and form a protective layer, while others alter the chemistry of urine itself, making it more alkaline and promoting the formation of mineral deposits that can block the catheter.
A large study across six hospitals found that men with catheters had roughly a 56% lower infection hazard compared to women with catheters, likely because of the longer urethra. Still, the absolute risk remains high with prolonged catheter use. If you’ve recently been hospitalized and had a catheter placed, a UTI in the days or weeks afterward is not unusual.
The Bacteria Behind Male UTIs
Most male UTIs are caused by gut bacteria that travel from the bowel to the urethral opening. E. coli is the most common culprit, but it accounts for only about 25% of male UTIs, a much smaller share than in women. Proteus and Providencia species cause a large portion of the remaining infections, with Klebsiella, Pseudomonas, and enterococci showing up less frequently. This broader range of bacteria is one reason male UTIs sometimes require a urine culture to guide treatment, since the infection may not respond to the antibiotics typically used for straightforward UTIs in women.
Diabetes and Immune-Related Risk
Poorly controlled diabetes increases UTI risk through a straightforward mechanism: when blood sugar is high, excess glucose spills into the urine. Sugar-rich urine is an ideal environment for bacteria to grow. People with type 2 diabetes are already at higher baseline risk for urinary infections, and certain diabetes medications that work by deliberately increasing glucose excretion through the kidneys can raise that risk further, particularly in the first six months of use. A weakened immune response from diabetes also makes it harder for the body to fight off infections once they start.
How to Tell a UTI From an STI
Several sexually transmitted infections produce symptoms that feel almost identical to a UTI, which can cause confusion. Chlamydia and gonorrhea both cause burning during urination, and most people with chlamydia have no symptoms at all, making it easy to miss. There are a few distinguishing features worth knowing:
- Urgency with an empty bladder is typical of a UTI but not an STI.
- Discharge from the penis points toward an STI rather than a UTI.
- Sores, bumps, or blisters on the penis, anus, or mouth suggest an STI.
- Foul-smelling or bloody urine is more characteristic of a UTI.
If you’re sexually active and experiencing painful urination, both possibilities are worth considering. Testing can distinguish between them quickly, and the treatments are different.
When a UTI Spreads
In men, an untreated UTI can spread to nearby organs in ways that don’t typically happen in women. Bacteria can travel from the urethra into the prostate, causing acute bacterial prostatitis, a painful condition with fever, chills, and difficulty urinating. Infection can also reach the epididymis, the coiled tube behind each testicle, leading to swelling and pain in the scrotum. Backward flow of infected urine into the prostate is one common route for this kind of spread. Treating a UTI promptly reduces the chance of these complications significantly.
Why Investigation Matters
Because UTIs in men usually have an identifiable cause, a single uncomplicated infection in a younger man may not raise alarms, but recurrent infections almost always warrant further evaluation. Imaging to check for stones or structural abnormalities, prostate assessment, and urine cultures to identify the specific bacteria involved are all standard next steps. Finding and addressing the underlying cause, whether it’s an enlarged prostate, a stricture, or poorly managed blood sugar, is typically more important than simply treating each infection as it arises.