The short version
Most sexually transmitted infections (STIs) in men cause no symptoms for weeks, months, or ever. That means "I feel fine" is not a test result, and the only way to know is to be tested. The good news is that the most common bacterial infections are curable, viral ones can be prevented or controlled, and testing is quick and often free or low cost.
- Get tested when you have a new partner, more than one partner, or a partner who tests positive, and at least once for HIV.
- Vaccinate against HPV (and hepatitis A and B where recommended).
- Ask about PrEP if you are at higher risk of HIV. Today it can be a daily pill or an injection every two or six months.
- Treat and tell partners if you test positive, so infections are not passed back and forth.
The common infections in men
| Infection | Symptoms in men (when present) | Treatment |
|---|---|---|
| Chlamydia | Discharge from the penis, burning with urination, testicular pain or swelling. Often none. | Antibiotics (curable) |
| Gonorrhea | Similar to chlamydia; can also infect the throat or rectum without symptoms. Antibiotic resistance is a growing concern. | Antibiotic injection (curable) |
| Syphilis | Usually a painless sore at first, later a rash (often including palms and soles) and other signs. Can be silent for years and then damage the heart and nervous system. | Penicillin (curable, especially if caught early) |
| HIV | Flu-like illness weeks after infection, then often nothing for years. | Daily medicine keeps the virus undetectable; a person with an undetectable viral load does not transmit HIV sexually |
| HPV | Usually none; some types cause genital warts, others raise the risk of cancers of the throat, anus, and penis. | No cure for the virus; warts can be treated; vaccine prevents it |
| Genital herpes (HSV) | Painful blisters or sores, or very mild symptoms that go unnoticed. Can spread even without visible sores. | Antivirals shorten outbreaks and reduce spread; no cure |
| Trichomoniasis | Often none in men; sometimes irritation or discharge. | Antibiotics (curable) |
Untreated chlamydia and gonorrhea can cause painful infection of the epididymis (the tube behind the testicle) and, in some cases, affect fertility. Syphilis cases in the United States have risen sharply in recent years, which is one reason testing matters even if you think your risk is low.
Who should be tested, and for what
The CDC's STI treatment guidelines and HIV recommendations are the basis for most clinic advice:
- HIV: everyone aged 13 to 64 should be tested at least once, and more often if at higher risk.
- Gay, bisexual, and other men who have sex with men: at least yearly testing for HIV, syphilis, chlamydia, and gonorrhea (at the sites of exposure, which can include the throat and rectum), and every 3 to 6 months if you have multiple or anonymous partners.
- Men who have sex only with women: guidelines do not call for routine chlamydia and gonorrhea screening without symptoms, but testing is reasonable with a new partner, several partners, symptoms, or a partner who tests positive. Ask a clinician to choose tests based on your situation.
- Before starting a new relationship or stopping condoms, testing together is a simple, low-drama habit.
Most tests need only a urine sample, a swab, or a blood draw. Many clinics, health departments, and Planned Parenthood centers offer confidential testing, and at-home kits exist for some infections. A negative result is only reliable after the "window period," the time an infection takes to show up, so repeat testing may be needed after a recent exposure.
Prevention that works
Condoms
Used correctly every time, condoms greatly reduce the risk of HIV, chlamydia, gonorrhea, and trichomoniasis. They help less with infections spread by skin contact outside the covered area (herpes, HPV, syphilis), so they lower risk without removing it.
HPV vaccine
The CDC recommends HPV vaccination for all children at age 11 to 12 (it can start at 9) and catch-up vaccination through age 26. Adults aged 27 to 45 who were not vaccinated can talk with a clinician about whether it makes sense for them, since benefit is smaller if you have already been exposed. The vaccine prevents genital warts and the HPV types that cause cancers in men and women. There is no routine HPV test for men, so prevention matters more than screening.
HIV prevention: PrEP, PEP, and treatment
- PrEP (pre-exposure prophylaxis) is medicine taken before exposure. Options now include a daily pill, an injection about every two months (cabotegravir), and a twice-yearly injection (lenacapavir). Taken as directed, PrEP lowers the risk of getting HIV from sex by roughly 99% in the case of the daily pill. It requires periodic HIV and kidney testing, which a prescriber arranges. Many insurers cover it, and assistance programs exist.
- PEP (post-exposure prophylaxis) is a month of medicine that must start within 72 hours of a possible exposure. Go to an emergency department or urgent care right away; sooner is better.
- Treatment as prevention: a person living with HIV who takes treatment and stays undetectable does not pass the virus to sexual partners.
Doxy-PEP
CDC guidance from 2024 says that men who have sex with men (and transgender women) who have had a bacterial STI in the past year can be offered doxycycline within 72 hours after sex to lower the risk of syphilis, chlamydia, and gonorrhea. It does not protect against viruses, and it needs a prescriber, so ask your clinic whether it fits.
If you test positive
- Take the full treatment exactly as prescribed, and avoid sex until you and your partners have been treated (your clinician will say how long).
- Tell recent partners so they can be tested and treated. Health departments can notify partners anonymously, and some clinicians can prescribe treatment for partners (expedited partner therapy).
- Get retested when advised. Repeat infections are common, and some infections need a follow-up test to confirm cure.
Sexual function and desire
Sexual health is more than infection prevention. Trouble with erections, low desire, or changes in ejaculation are common and often treatable, and they can signal something else going on, such as heart disease, diabetes, low testosterone, sleep apnea, depression, or a side effect of a medicine (antidepressants and BPH drugs are common causes). Start with these guides:
- ED and PDE5 inhibitors: how sildenafil and tadalafil work, who should avoid them, and how to avoid counterfeit pills.
- Low testosterone symptoms and the TRT guide: low desire is one of the more specific symptoms.
- Depression and anxiety and getting help: mood problems and their treatments often affect sex.
- Male fertility: if you are trying to conceive.
When to see a doctor
Get checked promptly for any of these:
- !Discharge from the penis, or burning when you urinate.
- !A sore, blister, wart, or new rash on the genitals, anus, or mouth.
- !Pain or swelling in a testicle. Sudden, severe testicular pain is an emergency (possible torsion).
- !A possible HIV exposure in the last 72 hours: ask for PEP now.
- !A partner who has told you they have an STI.
Sources
- Centers for Disease Control and Prevention. Sexually Transmitted Infections Treatment Guidelines, 2021.
- Centers for Disease Control and Prevention. HPV vaccination recommendations.
- Centers for Disease Control and Prevention. HIV testing, PrEP, and PEP guidance.
- Bachmann LH, et al. CDC Clinical Guidelines on the Use of Doxycycline Postexposure Prophylaxis for Bacterial Sexually Transmitted Infection Prevention, United States, 2024. MMWR Recomm Rep. 2024;73(2). CDC