About half of men with chlamydia never develop noticeable symptoms, which is one reason the infection spreads so easily. When symptoms do appear, they typically show up one to three weeks after exposure, though some men don’t notice anything for much longer. The most common signs involve the urethra (the tube you urinate through), but chlamydia can also affect the rectum, throat, and, if left untreated, the reproductive system.
Urethral Symptoms
The most recognizable sign of chlamydia in men is discharge from the penis. This discharge is often described as mucopurulent, meaning it looks cloudy or slightly off-white, sometimes with a yellowish or greenish tint. It can range from a thin, watery consistency to something thicker and more noticeable. Some men only see it first thing in the morning or notice staining in their underwear.
Painful or burning urination is the other hallmark symptom. The sensation is caused by inflammation inside the urethra, a condition called urethritis. Along with the burning, some men experience itching or tingling at the tip of the penis. These symptoms are easy to dismiss as minor irritation, which is part of why many men delay getting tested.
Why Half of Men Have No Symptoms
Roughly 50 percent of men with chlamydia are completely asymptomatic. They feel fine, have no discharge, and experience no pain. This doesn’t mean the infection is harmless. Chlamydia is still active, still transmissible to partners, and still capable of causing complications over time. The bacteria can quietly establish itself in reproductive tissue without triggering the kind of immune response that produces obvious symptoms.
This is why routine screening matters if you’re sexually active with new or multiple partners, even when nothing feels wrong.
Rectal and Throat Infections
Chlamydia doesn’t only infect the urethra. Men who have receptive anal sex can develop a rectal infection, which may cause rectal pain, discharge, or bleeding. In many cases, though, rectal chlamydia produces no symptoms at all.
Throat infections from oral sex are also possible. These are usually silent, rarely causing a sore throat or any noticeable discomfort. Because both rectal and throat infections are so often asymptomatic, they tend to go undiagnosed unless a clinician specifically tests those sites.
Testicular Pain and Swelling
When chlamydia goes untreated, the infection can travel deeper into the reproductive tract and inflame the epididymis, the coiled tube behind each testicle where sperm matures. This condition, called epididymitis, is one of the more serious complications in men.
Epididymitis typically affects one side. You’d notice a gradual onset of pain and tenderness in one testicle, along with swelling that may spread from the back of the testicle to the testicle itself. The spermatic cord (the structure running from the testicle up into the abdomen) often becomes tender and swollen too. Some men develop fluid buildup around the testicle, which makes the scrotum feel heavier than usual. Without treatment, this inflammation can become severe enough to affect daily activities.
Effects on Fertility
There’s growing evidence that chlamydia can damage male fertility, even in men who never had symptoms. Researchers at the Hudson Institute of Medical Research found chlamydia bacteria in testicular tissue biopsies from men whose infertility had no other identified cause. Of 18 men who provided fresh tissue samples, 12 had blood antibodies confirming prior exposure to chlamydia, yet none of them had ever been diagnosed with the infection or reported any symptoms.
Animal studies from the same research group show that chlamydia can establish a chronic infection in the testes and significantly impair normal sperm development. While more research is needed to fully understand how common this is, the findings suggest that untreated chlamydia may quietly interfere with sperm production and quality well before a man ever tries to conceive.
Reactive Arthritis
A less common but notable complication is reactive arthritis, an inflammatory condition triggered by the body’s immune response to the infection. The classic pattern involves three areas at once: joint inflammation, eye redness and irritation, and urinary tract symptoms like painful or frequent urination.
Joint pain and stiffness tend to hit the lower back, knees, ankles, and feet. The eye symptoms can include swelling, redness, and discomfort. Not everyone gets the full triad, and symptoms can appear weeks after the initial infection. Reactive arthritis is more common in men than women and can persist for months, though it usually resolves with appropriate treatment of the underlying infection.
How Testing Works
The standard test for chlamydia in men is a nucleic acid amplification test, commonly called a NAAT. For urethral infections, this can be done with either a urine sample or a swab from inside the urethra. In practice, most clinicians offer the urine test first because it’s noninvasive and has strong sensitivity for detecting the bacteria. Urethral swabs may be slightly more sensitive in asymptomatic men, but urine testing is considered adequate for screening and is far more acceptable to most patients.
If you’ve had receptive anal or oral sex, separate swab tests from the rectum or throat are needed. A urine test won’t detect infections at those sites.
What Treatment Looks Like
Chlamydia is curable with antibiotics. The current first-line treatment recommended by the CDC is a seven-day course of an oral antibiotic taken twice daily. This regimen has proven more effective than the older single-dose alternative, particularly for rectal infections. When the seven-day course isn’t practical (for example, if there’s concern about completing the full week), a single-dose option is still available, though it may require a follow-up test to confirm the infection has cleared.
During treatment, you should avoid sexual contact for at least seven days after completing the medication. Sexual partners from the past 60 days need to be notified and treated as well, even if they have no symptoms. Reinfection is common, so retesting about three months after treatment is generally recommended.