Men get urinary tract infections when bacteria, most commonly from the gut, travel into the urethra and take hold in the urinary system. While UTIs are far less common in men than in women, they do happen, and the risk increases significantly with age. Understanding why men are usually protected and what breaks down that protection helps explain who’s most vulnerable and what can be done about it.
Why Men Are Naturally Protected
The male urethra is roughly 7 to 8 inches long, compared to about 1.5 inches in women. That difference matters enormously. Bacteria have to travel a much greater distance to reach the bladder, and urine flowing outward flushes most of them away before they can establish an infection. This built-in barrier is the main reason UTIs in younger men are relatively rare.
The prostate gland also contributes some protection. It produces secretions with antibacterial properties that help keep the urinary tract sterile. So for a man to develop a UTI, something typically has to compromise these natural defenses.
The Most Common Causes in Men
The bacteria responsible for male UTIs almost always originate in the gastrointestinal tract. E. coli is the most common culprit, causing about 25% of male UTIs (and up to 80% of infections linked to chronic prostate involvement). Other gut bacteria like Proteus, Klebsiella, and Enterococcus species account for much of the rest. These organisms reach the urethral opening and, given the right conditions, migrate inward.
Several factors create those conditions:
- Enlarged prostate (BPH): As the prostate grows, it squeezes the urethra and blocks normal urine flow. When the bladder can’t fully empty, leftover urine becomes a breeding ground for bacteria. This is the single biggest reason UTIs become more common in men after age 50.
- Urinary catheters: Any tube placed into the bladder introduces bacteria directly past the body’s defenses. Long-term catheter use is a major risk factor, partly because certain bacteria form a sticky film on the catheter surface that resists both the immune system and antibiotics.
- Kidney stones or structural abnormalities: Anything that blocks or slows urine flow, whether a stone, a narrowed urethra, or an anatomical variation, creates pockets of stagnant urine where bacteria thrive.
- Weakened immune system: Conditions like diabetes or immune-suppressing medications reduce the body’s ability to fight off bacteria that enter the urinary tract.
- Recent urologic procedures: Surgery or diagnostic procedures involving the urinary tract can introduce bacteria, even with sterile technique.
Urethritis vs. a True UTI
Not every burning sensation during urination is a UTI. In sexually active men, especially those under 35, the symptoms may actually come from urethritis, an infection of the urethra itself caused by sexually transmitted organisms rather than gut bacteria. The distinction matters because the treatment is completely different.
Urethritis typically produces a visible discharge from the penis along with itching or tingling. A true UTI is more likely to cause urgency, frequent urination, blood in the urine, and waking up at night to pee, usually without discharge. Men over 35 with UTI symptoms are more likely to have a standard bacterial infection, often related to prostate changes, while younger men with discharge should be evaluated for a sexually transmitted cause. Your doctor can sort this out quickly with a urine test: the presence of nitrites on a dipstick test points toward a standard UTI rather than urethritis.
What a Male UTI Feels Like
The symptoms overlap with what women experience but can have some distinct features depending on where the infection settles. A bladder infection (cystitis) causes a burning feeling when you urinate, a persistent urge to go even when your bladder is nearly empty, cloudy or foul-smelling urine, and sometimes visible blood.
If infection spreads to the prostate, you may notice deep pelvic or perineal pain, difficulty starting your urine stream, and pain during or after ejaculation. A kidney infection (pyelonephritis) typically brings fever, chills, flank pain, nausea, and a general feeling of being very unwell. Fever in particular is a signal that the infection may have moved beyond the bladder and needs prompt attention.
How Male UTIs Are Diagnosed
A urine sample is the foundation of diagnosis. A culture showing more than 100,000 bacterial colonies per milliliter is generally considered diagnostic for a UTI. But the clinical picture matters too. Your doctor will ask about your symptoms, sexual history, and any urinary problems you’ve been having. Because UTIs in men are less common and more likely to involve a complicating factor, doctors typically investigate further than they might for a straightforward UTI in a woman. That may mean imaging of the urinary tract or a prostate exam to look for enlargement or tenderness.
Treatment and Recovery Timeline
Male UTIs are treated with antibiotics, but the course is usually longer than what women receive for a simple bladder infection. Current guidelines recommend 5 to 7 days of treatment for a straightforward complicated UTI. If the infection involves the prostate, treatment often extends to 10 to 14 days because antibiotics take longer to penetrate prostate tissue effectively.
Most men start feeling better within 2 to 3 days of starting antibiotics, but finishing the full course is important to clear the infection completely. If bacteria have entered the bloodstream, a 7-day course of antibiotics is typically sufficient as long as symptoms are improving. Your doctor will likely want a follow-up urine test after treatment to confirm the infection has resolved, which is standard practice for men but not always done for women with uncomplicated UTIs.
What Happens if a UTI Goes Untreated
Male UTIs are considered complicated by default because of the prostate’s involvement in the urinary tract. An untreated bladder infection can spread to the prostate (acute bacterial prostatitis), which causes severe pelvic pain, high fever, and difficulty urinating. Chronic bacterial prostatitis is actually the most common cause of recurring UTIs in men, creating a cycle where the prostate harbors bacteria that repeatedly seed new infections.
Infection can also spread to the epididymis (the coiled tube behind each testicle), causing painful swelling in the scrotum. In the worst case, bacteria enter the bloodstream and cause urosepsis, a life-threatening condition requiring emergency care. These complications are why male UTIs generally warrant more thorough evaluation and treatment than a simple UTI in a woman.
Reducing Your Risk
Staying well-hydrated is the simplest and best-supported preventive measure. Water is ideal. Adequate fluid intake keeps urine flowing regularly, which physically flushes bacteria out of the urinary tract before they can multiply.
If you have an enlarged prostate, managing it effectively is one of the most important things you can do to prevent UTIs. When the bladder empties completely, bacteria lose their foothold. Men who use catheters can reduce risk through careful hygiene and, when possible, minimizing how long the catheter stays in place. Urinating after sexual activity helps clear bacteria from the urethra, a habit that benefits men just as it does women.