Men get urinary tract infections when bacteria enter the urethra and travel into the bladder or, in some cases, the kidneys or prostate. While UTIs are far more common in women, men are not immune, and the causes in men often point to specific underlying factors that make infection more likely. Understanding those factors is the key to knowing why it happened and how to lower the risk of it happening again.
How Bacteria Get Into the Urinary Tract
The most common culprit is E. coli, a bacterium that normally lives in the gastrointestinal tract. It typically reaches the urethra from the outside, and once inside, it can colonize the bladder lining and trigger infection. Other bacteria can cause UTIs too, but E. coli is responsible for the majority of cases in both men and women.
In men, the urethra is significantly longer than in women, which is why male UTIs are less common. Bacteria have a longer distance to travel before reaching the bladder. But when other factors slow urine flow or introduce bacteria directly, that anatomical advantage shrinks considerably.
Enlarged Prostate: The Most Common Cause in Older Men
Benign prostatic hyperplasia (BPH), or an enlarged prostate, is the single biggest risk factor for UTIs in men over 50. As the prostate grows, it presses against the bladder and pinches the urethra. This slows or partially blocks the flow of urine. Over time, the bladder muscle weakens from pushing against that narrowed passage, and the bladder stops emptying completely.
That leftover urine is the problem. Stagnant urine sitting in the bladder becomes a breeding ground for bacteria. If you’ve noticed a weak stream, difficulty starting urination, or a feeling that your bladder isn’t fully empty, those symptoms suggest incomplete emptying, which raises your infection risk significantly. BPH doesn’t cause UTIs directly, but it creates the conditions bacteria thrive in.
Catheters and Medical Procedures
Urinary catheters are one of the most well-documented causes of UTIs in men, particularly in hospital settings. A catheter bypasses the body’s natural defenses by providing a direct pathway for bacteria to enter the bladder. Research published in BMJ Open found a 7.4% risk of infection in the first 24 hours after catheter insertion, with the risk climbing by about 8% each additional day for the first week. The longer a catheter stays in, the higher the odds of infection.
Other procedures involving the urinary tract, such as cystoscopy (a scope inserted into the bladder) or prostate surgery, can also introduce bacteria. If you’ve recently had any urinary procedure and develop burning during urination or increased urgency, that’s worth flagging promptly.
Sexual Activity and STIs That Mimic UTIs
Sexual activity can introduce bacteria into the urethra. Anal intercourse carries higher risk because it increases the chance of E. coli reaching the urethral opening. Unprotected sex of any kind can also expose the urethra to unfamiliar bacteria.
It’s worth knowing that sexually transmitted infections like chlamydia and gonorrhea can feel almost identical to a UTI. Both cause painful, burning urination. The key differences: STIs tend to cause discharge from the penis and don’t typically produce that urgent “need to go” feeling when the bladder is empty. UTIs cause urgency but generally don’t cause discharge. Most people with chlamydia don’t have symptoms at all, which makes testing important. A urine test can diagnose both UTIs and several common STIs, so your provider can sort out which one you’re dealing with from a single sample in many cases.
Diabetes and Immune Function
Poorly controlled blood sugar increases UTI risk in several ways. High glucose levels in urine essentially feed bacteria, giving them more fuel to multiply. Diabetes also impairs immune function over time, making it harder for the body to fight off infections before they take hold. Men with diabetes who also have nerve damage affecting the bladder (a common complication) may not fully empty their bladder, compounding the problem the same way BPH does.
Kidney Stones and Structural Blockages
Anything that physically obstructs urine flow creates the same stagnation risk as an enlarged prostate. Kidney stones lodged in the ureter can block or slow drainage from the kidney, allowing bacteria to multiply upstream. Urethral strictures, which are areas of scar tissue that narrow the urethra (sometimes from prior injury, infection, or surgery), have the same effect. If you’ve had recurrent UTIs as a male, your provider will likely look for a structural cause, because in men there usually is one.
Symptoms to Recognize
Male UTI symptoms overlap significantly with those in women: burning or stinging during urination, frequent urges to urinate (especially with little urine coming out), cloudy or strong-smelling urine, and pelvic or lower abdominal discomfort. Blood in the urine can occur but isn’t always present.
Where male UTIs differ is that they’re more likely to involve the prostate. If the infection spreads to the prostate, you may develop fever, chills, pain between the scrotum and rectum, or deep pelvic aching. About one in nine men with acute bacterial prostatitis go on to develop a chronic form of prostatitis or chronic pelvic pain, so infections involving the prostate warrant close follow-up.
How Male UTIs Are Diagnosed
Diagnosis relies on a urine culture. In men, a culture growing more than 1,000 colony-forming units per milliliter is considered positive, which is a lower threshold than what’s used for women. This lower cutoff has both high sensitivity and specificity (97% for each), meaning it catches nearly all true infections while rarely producing false positives. Your provider will also want to identify the specific bacterium so they can choose an antibiotic it’s susceptible to.
Treatment and Recovery
Because male UTIs are more likely to involve deeper structures like the prostate, they’re generally treated with longer antibiotic courses than the short regimens women often receive. For a complicated UTI or one involving the kidneys, current guidelines recommend 5 to 7 days of treatment. If bacterial prostatitis is suspected, your provider may extend that to 10 to 14 days.
Most men start feeling better within 48 to 72 hours of starting antibiotics, but finishing the full course matters. Stopping early can leave resistant bacteria behind, setting the stage for recurrence. During treatment, drinking plenty of water helps flush bacteria from the bladder more efficiently.
Lowering Your Risk
For men with an enlarged prostate, treating the underlying BPH is the most effective way to prevent recurrent UTIs. Medications that relax the prostate or shrink it can improve bladder emptying. Staying well hydrated keeps urine dilute and flowing regularly, which limits the time bacteria have to multiply. Urinating soon after sex reduces the chance of bacteria establishing themselves in the urethra.
If you use a catheter at home, clean technique and limiting how long the catheter stays in place are the two biggest levers for reducing infection risk. Men with diabetes benefit from keeping blood sugar well controlled, both for UTI prevention and for dozens of other reasons. And if you’re experiencing symptoms that could be a UTI or an STI, getting tested rather than guessing ensures you get the right treatment the first time.