This page is general health information, not medical advice. It cannot tell you whether you have an infection. A clinician can, and the testing options on this site are a good place to start.

Many sexually transmitted infections cause no symptoms at all in men. When symptoms do appear, they can look like many other conditions. That is why this guide covers two things: the signs that are linked to each infection, and the reasons testing is useful even when nothing feels different.

This is a science-focused look at STD symptoms in men. It covers the organisms involved, what research suggests, the safety profile of testing and treatment, and how to judge a testing source. It ends with free and low-cost options in San Antonio.

It cannot tell you whether you have an infection. Only a test and a clinician can do that.

Why symptoms are an unreliable guide

The CDC STI Treatment Guidelines (2021) note that chlamydia, gonorrhea, trichomoniasis and several other infections are often present without any signs in men. Infections in the throat and rectum are especially likely to be silent.

This matters for a simple reason. A person with no symptoms can still have an infection, can still pass it to a partner, and can still develop complications if it goes untreated. A normal-feeling body is not the same as a negative result.

The reverse is also true. Burning, discharge or a sore does not tell you which infection is involved, or whether it is an infection at all. Skin irritation, a urinary tract infection and other common conditions can look similar.

The organisms behind the symptoms

A deep dive into this topic does not involve ingredients or compounds. It involves the organisms that cause these infections. Knowing what they are explains why treatment and testing differ.

Bacteria: Chlamydia trachomatis (chlamydia), Neisseria gonorrhoeae (gonorrhea), Treponema pallidum (syphilis) and Mycoplasma genitalium. The CDC says bacterial STIs are curable with treatment from a clinician.
A parasite: Trichomonas vaginalis (trichomoniasis). The CDC also lists it as curable with treatment from a clinician.
Viruses: HIV, herpes simplex virus (HSV) and human papillomavirus (HPV). The CDC says these are not curable, but they are treatable or manageable. Modern HIV treatment can bring the amount of virus in the blood to very low levels.

The type of organism decides the type of test. Bacterial infections of the urethra, throat and rectum are usually detected with nucleic acid amplification tests, or NAATs, which look for the organism's genetic material. HIV is detected with blood tests. Syphilis is detected with blood tests, plus a clinician's exam of any sore.

Signs by infection

The signs below are the ones the CDC describes most often. None of them confirms an infection, and their absence does not rule one out.

Chlamydia and gonorrhea

The CDC describes similar signs for both. They can include burning when urinating, discharge from the penis, and pain or swelling in one or both testicles. Some people notice itching or irritation at the tip of the penis.

Rectal infection can cause pain, discharge or bleeding, but the CDC says it often causes nothing noticeable. A throat infection with gonorrhea or chlamydia usually has no symptoms either.

Syphilis

The CDC describes syphilis in stages. The first stage often shows up as one or more sores, called chancres, which are usually firm and painless. Because they do not hurt, they can go unnoticed, especially if they are inside the rectum or mouth.

The secondary stage can bring a rash, often on the palms and soles, along with fever, swollen glands or patchy hair loss. These signs can fade without treatment while the infection remains. Syphilis can be diagnosed and treated at any stage by a clinician.

Genital herpes

The CDC says many people with genital herpes have mild symptoms or none. When symptoms occur, they can include small blisters or open sores, tingling, itching or pain in the genital or anal area. A first episode may also come with fever or body aches. Herpes is treatable and manageable, and a clinician can discuss options.

HPV

Most HPV infections cause no symptoms, according to the CDC. Some types cause genital warts, which are small bumps or flat areas of skin. Other types are linked to cancers of the throat, anus and penis over many years.

The CDC states there is no approved routine HPV test for men. A clinician can examine visible warts, and HPV vaccination is a topic worth raising at any visit.

Trichomoniasis

The CDC notes that most men with trichomoniasis have no symptoms. Some have irritation inside the penis, discharge, or burning after urinating or ejaculating.

HIV

Some people have flu-like symptoms such as fever, sore throat, rash or swollen glands within a few weeks of HIV infection, according to the CDC. Many have no early symptoms. The only way to know is a test.

Why throat and rectal tests are separate

A urine sample checks the urethra. It does not check the throat or the rectum.

Gonorrhea and chlamydia can live at each of these sites separately. The CDC STI Treatment Guidelines recommend testing the sites that were exposed. For men who have sex with men, the CDC recommends testing the urethra, rectum and throat based on the types of sex a person has had.

There are practical reasons this is easy to miss:

Throat and rectal infections often cause no symptoms.
A urine test can be negative while a throat or rectal infection is present.
Each site is sampled with a swab, which is usually quick. Many clinics allow self-collected swabs.

If you are not sure what to ask for, you can describe what kinds of sex you have had. A clinician can then choose which sites to sample. This applies to every gender and orientation, not only to men who have sex with men.

What research suggests

The points below are observations from public health research. They describe patterns across large groups of people, not what is true for any one person.

Research suggests that untreated chlamydia and gonorrhea can lead to complications in men, such as inflammation of the tube behind the testicle called epididymitis, according to the CDC STI Treatment Guidelines (2021).
Research suggests that having an STI can make it easier to acquire or pass on HIV. The CDC describes this link in its HIV prevention materials.
Studies summarized by the CDC suggest that routine screening finds infections that would otherwise go unnoticed, because so many are silent.
In 2024, the CDC updated its guidance on doxycycline taken after sex (doxy-PEP). The CDC suggests it can lower the chance of syphilis, chlamydia and gonorrhea for some people. The CDC's guidance applies to men who have sex with men and transgender women who have had a bacterial STI in the past 12 months. It is prescribed by a clinician, who can explain who it is for and what to expect.

When to test

The CDC recommends at least yearly testing for chlamydia, gonorrhea, syphilis and HIV for sexually active gay, bisexual and other men who have sex with men. Some may benefit from testing every 3 to 6 months, depending on risk. The CDC also recommends HIV screening at least once for everyone aged 13 to 64, and the USPSTF recommends the same for ages 15 to 65.

Other reasons to test include:

A new partner, or a partner who has been told they have an STI
Any new symptoms, however mild
Sex without a condom, or a condom that broke or slipped
Wanting a baseline before starting a new relationship

Window periods

A window period is the time between exposure and when a test can reliably detect an infection. For HIV, the CDC says a nucleic acid test can detect infection about 10 to 33 days after exposure. An antigen/antibody test done on blood drawn from a vein can detect it about 18 to 45 days after exposure. Rapid antigen/antibody tests done with a fingerstick take longer, about 18 to 90 days.

For other infections, window periods vary by test and organism. A clinician can say when testing makes sense after a specific exposure and whether a repeat test is useful.

When to see a clinician the same day

Some situations should not wait for a routine appointment. Seek care the same day, at an urgent care or emergency room if needed, for:

Sudden, severe testicular pain, especially with nausea. This can be a medical emergency that is not an infection. Do not wait to see if it settles.
Fever with genital pain, swelling or discharge.
Possible HIV exposure in the past 72 hours. The CDC says post-exposure prophylaxis (PEP) must be started within 72 hours to be considered. A clinician prescribes it. AARC and Kind Clinic list PEP among their services.
Vision changes, eye pain or hearing changes in someone who has had syphilis or a possible exposure. The CDC notes that syphilis can affect the eyes and ears.
A widespread rash with fever that appeared after a possible exposure.

Safety profile of testing and treatment

Testing itself is low risk. Urine and swab samples are painless or mildly uncomfortable. Blood draws and fingersticks cause brief discomfort.

A few safety points are worth knowing:

False results can occur. Testing too soon after exposure can miss an infection. Rarely, a test can be positive when no infection is present. That is why clinics confirm some results.
Treatment is prescribed, not self-selected. A clinician chooses medication based on the infection, the site, allergies, other medicines and pregnancy status. Taking leftover or shared antibiotics can hide symptoms without clearing an infection.
Allergies and interactions matter. Tell the clinician about any drug allergies and any medicines you take.
Partners can be treated too. The CDC lists Texas as a place where expedited partner therapy has a legal basis through administrative rules, which can let a clinician provide medication for a partner. Ask the clinic whether it applies to your situation.
Retest when advised. The CDC recommends retesting after treatment for some infections, because reinfection is common.

Quality indicators: how to judge a testing source

In this case, quality is not about a product. It is about how a testing source works. These signs suggest a reliable one:

It is run by a health department, a community health center or a recognized nonprofit.
It tests the sites that were exposed, not only urine.
It uses NAATs for gonorrhea and chlamydia and blood tests for syphilis and HIV.
It explains when results will be ready and how you will be told.
It has a way to connect you with treatment, or tells you where to go for it.
It is clear about costs, identification requirements and confidentiality.

Where to test in San Antonio

Several free and low-cost options serve San Antonio. Details can change, so confirm hours and requirements with the clinic before you go. You can also compare more options on our list of places to get tested in San Antonio.

For a national search tool, the CDC offers GetTested, where you can look up testing locations by ZIP code.

Local rates, for context

The Texas Department of State Health Services (DSHS) reported 5,983 gonorrhea cases in Bexar County in 2022, a rate of 290.5 per 100,000 people. The Texas rate that year was 207.0. DSHS also reported 500 primary and secondary syphilis cases in Bexar County in 2022, a rate of 24.3 per 100,000, against 15.5 for Texas. DSHS reported 12,305 chlamydia cases in Bexar County in 2022. The report does not print a county rate for chlamydia.

For HIV, the CDC's 2024 surveillance tables show 373 new diagnoses in Bexar County, a rate of 21.1 per 100,000 people aged 13 and older. The Texas rate for the same age group was 19.4. These are counts of reported cases, so they reflect who was tested as well as who was infected.

Clinics

Clinic	Address and phone	Cost and hours
Metro Health STI Walk-In Clinic	512 E. Highland, Suite 150, San Antonio, TX 78210. 210-207-8830	$15 office visit administrative fee; other fees vary by service. Mon to Thu 7:45 a.m. to 4:30 p.m. (latest check-in 3 p.m.). Fri 7:45 a.m. to 12 p.m. (latest check-in 10:30 a.m.). Check-in may close early at capacity.
San Antonio AIDS Foundation	818 E. Grayson Street, San Antonio, TX 78208. (210) 225-4715	Free. Mon 8:30 to 4; Tue 12 to 8; Wed and Thu 8:30 to 4; Fri 9 to 1; Sat 11 to 3; closed Sun. No appointment needed.
Alamo Area Resource Center	303 N. Frio, San Antonio, TX 78207. (210) 625-7200	Free. Walk-ins Mon to Fri 8 a.m. to 4:30 p.m., and Wednesday until 8 p.m.
Kind Clinic, San Antonio	730 Isom Road, San Antonio, TX 78216. 833-937-5463 (general support line)	Free walk-in testing. Clinic hours: Mon, Tue and Fri 9 a.m. to 5 p.m.; Wed and Thu 9 a.m. to 8 p.m.; 2nd and 4th Saturdays 9 a.m. to 2 p.m. Walk-in testing hours differ, so ask.
BEAT AIDS	210.212.2266. Call for the testing location.	Free and confidential testing. Call to confirm walk-in availability.
CommuniCare Apollo Wellness Clinic	6511 W Loop 1604 N, Ste. 105, San Antonio, TX 78254. (726) 224-3438	Sliding fee for self-pay patients with family income under 200% of federal poverty guidelines. Mon to Fri 8 a.m. to 5 p.m.
CentroMed	Administration office: 3750 Commercial Ave, San Antonio, TX 78221. 210-922-7000	Sliding fee scale by income and family size. Its page lists STD screening and treatment under women's services, so ask which sites serve men.

What to know before you go

Metro Health requires a photo ID and does not test anonymously. The clinic serves residents of San Antonio and Bexar County and people with no other means of getting STI services, according to Metro Health. Call 210-207-8830 if you are unsure whether you qualify.
Lab results take time. The San Antonio AIDS Foundation says gonorrhea and chlamydia results come back in 7 to 10 days through the DSHS lab. Its page lists rapid HIV and syphilis testing as well.
Rapid tests have limits. AARC lists rapid HIV, syphilis and hepatitis C tests by fingerstick, and also lists PrEP and PEP. A clinician can explain which test fits your timeline.
Treatment is not at every site. Metro Health and Kind Clinic list treatment among their services. Ask any other site where treatment is available if a result is positive.
PrEP and doxy-PEP. Metro Health runs a PrEP Clinic at 512 E. Highland Blvd., Ste. 150 (210-207-7292), and its page says walk-ins are accepted but appointments are highly encouraged. San Antonio AIDS Foundation lists doxy-PEP among its services. Kind Clinic says doxy-PEP is available to its own patients only.

Privacy, teens and reporting

Under Texas Family Code Section 32.003, a minor of any age may consent to diagnosis and treatment of a reportable infectious disease. That covers reportable STIs and HIV, and parent consent is not required. The same section allows a physician to tell a parent or guardian about the treatment. Teens should ask a clinic how it handles this before their visit.

DSHS lists chlamydia, gonorrhea, syphilis and HIV as notifiable conditions in Texas. That means labs and clinicians report positive results to the health department. Health departments use these reports to track trends and to offer partner services.

Texas has no HIV-specific or STD-specific criminal exposure law, according to the CDC's 2023 analysis. General criminal laws can still apply in some situations. If you have questions about your own circumstances, a legal aid organization can help.

What to do next

If you have symptoms, are not sure about an exposure, or simply have not tested in a while, the next step is a test. It is a routine part of health care, and every clinic listed above sees people of every gender and orientation without judgment.

Start with the option that best fits your schedule and budget. If you want to compare other locations, use the CDC's GetTested tool or contact Metro Health.

STD Symptoms in Men: Signs, When to Test and Where in San Antonio