Men get urinary tract infections when bacteria enter the urethra and travel up into the bladder. While UTIs are far more common in women, men develop them too, especially after age 50. The longer male urethra provides some natural protection by making it harder for bacteria to reach the bladder, but several conditions and behaviors can override that advantage.
How Bacteria Enter the Male Urinary Tract
The most common culprit is E. coli, a bacterium that normally lives in the gastrointestinal tract. When these bacteria migrate from the bowel area to the opening of the urethra, they can travel upward into the bladder and multiply. This is the same basic mechanism behind most UTIs in both men and women.
Sexually transmitted infections can also cause inflammation of the urethra specifically. Gonorrhea, chlamydia, herpes, and mycoplasma can all infect the urethra after sexual contact, producing symptoms that overlap with a traditional UTI. These require different treatment than a standard bacterial infection, which is one reason testing matters when symptoms appear.
The Role of an Enlarged Prostate
An enlarged prostate is one of the most significant risk factors for UTIs in men, and it explains why infections become more common with age. As the prostate grows, it presses against the bladder and pinches the urethra, slowing or partially blocking urine flow. Over time, the bladder muscle weakens from straining against this narrowed passage, and the bladder stops emptying completely.
That leftover urine is the problem. Stagnant urine sitting in the bladder creates a warm, nutrient-rich environment where bacteria thrive. Instead of being flushed out regularly, bacteria have time to multiply and establish an infection. This is why men with prostate enlargement often deal with recurring UTIs rather than a single isolated episode.
Kidney Stones and Other Blockages
Anything that blocks or slows urine flow raises infection risk through the same basic mechanism: urine that can’t drain properly becomes a breeding ground. Kidney stones are a common example. A stone lodged in the ureter or urethra physically obstructs the path of urine, and an infection can form behind that blockage. A narrowed urethra from scarring (sometimes caused by previous infections, injuries, or medical procedures) creates a similar situation.
A weakened immune system compounds the problem. Conditions like diabetes and HIV reduce the body’s ability to fight off bacteria that enter the urinary tract. For men with diabetes specifically, elevated blood sugar can impair immune cell function while also promoting bacterial growth, making infections both more likely and harder to clear.
Sexual Activity and UTI Risk
Sex is a well-known trigger for UTIs in women, but it affects men too. Any type of sexual activity can move bacteria from the skin around the genitals to the urethral opening, where it can travel upward into the bladder. You have large numbers of bacteria on the outside of your genitals under normal circumstances, and physical contact during sex redistributes them.
Men’s longer urethra means bacteria have farther to travel, which is why post-sex UTIs are less frequent in men than in women. But the protection isn’t absolute, particularly for men who already have other risk factors like incomplete bladder emptying or a compromised immune system.
Why Male UTIs Are Taken More Seriously
In clinical terms, UTIs in men are generally classified as complicated infections regardless of how mild the symptoms seem. This isn’t because the infection itself is necessarily worse, but because UTIs are uncommon enough in men that their presence often signals an underlying issue: a prostate problem, a structural abnormality, or an immune deficiency. The infection you notice may be a symptom of something else going on.
This classification has practical consequences. Men typically receive longer courses of antibiotics than women with the same type of infection. Where a woman with an uncomplicated bladder infection might take antibiotics for five days, a man with the same infection is more likely to be treated for seven days. Your doctor may also order imaging or additional tests to look for the structural or functional problem that allowed the infection to develop in the first place.
Complications to Watch For
A UTI that starts in the bladder can spread deeper into the urinary tract if left untreated. One particular concern for men is bacterial prostatitis, an infection of the prostate gland. Men with lower urinary tract infections are more likely to develop this condition, and UTIs that recur or prove difficult to treat can lead to chronic bacterial prostatitis, a persistent infection that causes pelvic pain, painful urination, and difficulty emptying the bladder.
Chronic prostatitis sometimes develops even after the original UTI has been treated. The immune system’s response to a previous infection, or chemical changes in the urine, can trigger ongoing inflammation in the prostate that persists long after bacteria have been cleared. If a bladder infection spreads upward to the kidneys instead, it becomes a kidney infection, which can cause fever, back pain, nausea, and in severe cases, dangerous bloodstream infections.
Recognizing the Symptoms
Male UTI symptoms largely mirror what women experience: a burning sensation during urination, frequent or urgent need to urinate, cloudy or strong-smelling urine, and pelvic discomfort. Some men also notice blood in their urine. If the infection involves the prostate, you may feel pain between the scrotum and rectum, experience painful ejaculation, or have difficulty starting your urine stream.
Fever, chills, nausea, or pain in your back or side suggest the infection has moved beyond the bladder to the kidneys. These symptoms call for prompt medical attention since kidney infections can progress quickly.
Reducing Your Risk
The CDC recommends several straightforward habits to lower UTI risk. Urinating after sexual activity helps flush bacteria that may have been pushed toward the urethra. Staying well hydrated keeps urine flowing regularly, which prevents bacteria from settling in the bladder. Showers are preferable to baths, since sitting in bathwater can introduce bacteria to the urethral opening. Avoiding sprays, powders, or other products in the genital area also reduces irritation and bacterial disruption.
For men with an enlarged prostate, managing that underlying condition is the most effective UTI prevention strategy. If you’re not emptying your bladder fully, no amount of hydration or hygiene will eliminate the infection risk created by stagnant urine. Addressing the obstruction, whether through medication or a procedure, treats the root cause rather than just the infections it produces.