STD Testing and Treatment — What to Test For, When, and Why

The single most important thing to understand about sexually transmitted infections is that most of them cause no symptoms. Chlamydia is silent in the large majority of people who have it. Gonorrhea often is too. Early syphilis can produce a painless sore that heals on its own and is never noticed. HIV can go years without producing anything a person would connect to an infection.

That is the entire reason screening exists. If you wait to be tested until something feels wrong, you will miss most infections — including the ones that go on to cause pelvic inflammatory disease, tubal infertility, chronic pelvic pain, or complications in pregnancy. Testing is not something you do because you suspect a problem. It is something you do on a schedule, the way you get a blood pressure check.

Which infections we test for

Not every STI panel includes everything, and that surprises people. What we test for depends on your age, your anatomy, whether you are pregnant, and your specific exposures.

• Chlamydia and gonorrhea — the two most commonly reported bacterial STIs, and the two most likely to be silent.
• HIV
• Syphilis — rates have risen sharply in the United States over the past decade, including congenital syphilis in newborns.
• Trichomoniasis — a parasite, very common, often mistaken for a yeast infection or bacterial vaginosis.
• Hepatitis B and hepatitis C
• Herpes simplex (HSV) — tested by swabbing a lesion when one is present. Routine blood testing for herpes in people without symptoms is not recommended, because the blood tests produce a meaningful number of false positives and a positive result in someone with no symptoms rarely changes what we do.
• HPV — screened through cervical cancer screening rather than as part of an STI panel. That schedule is covered in routine check-ups.

The screening schedule

These are the current CDC recommendations, and they are worth knowing well enough to ask for what you need.

Chlamydia and gonorrhea. Annual screening for all sexually active women under 25. Age 25 and older, annual screening if you have risk factors — a new partner, more than one partner, a partner who has other partners, or a partner with an STI. In pregnancy, screening at the first prenatal visit, and again in the third trimester if you are under 25 or have risk factors.

HIV. At least once for everyone between 13 and 64, as a normal part of medical care. More often — at least annually — if you have ongoing risk. HIV testing is part of standard prenatal care in every pregnancy.

Syphilis. In every pregnancy, at the first prenatal visit. Repeat testing in the third trimester and again at delivery is recommended for people at increased risk or living in areas with high syphilis rates. Outside of pregnancy, testing is based on risk.

Hepatitis C. At least once in adulthood for everyone 18 and older, and in every pregnancy.

Hepatitis B. In every pregnancy, and at least once in adulthood for adults who have not been screened.

Trichomoniasis. Not screened universally, but tested for when there are symptoms and considered for people with risk factors.

The right answer for you may be more frequent than the baseline. If you have had a recent partner change, if a partner has told you about an exposure, or if you simply want the reassurance, ask — a request for testing is always reasonable and never needs a justification.

What testing actually involves

Far less than most people expect.

Chlamydia and gonorrhea are diagnosed with a nucleic acid amplification test, or NAAT — the most sensitive test available. For a vaginal specimen, a self-collected vaginal swab is as accurate as one collected by a clinician, and you can do it yourself in the bathroom in under a minute. A urine sample also works. If you have oral or anal exposure, those sites need their own swabs, because a urine or vaginal test will not find an infection in the throat or rectum. This matters more than it sounds — pharyngeal and rectal infections are common and are routinely missed when only one site is tested.

HIV, syphilis, and hepatitis are blood tests, drawn together with anything else you need. Rapid HIV tests using a fingerstick are available and give results in about twenty minutes.

Trichomoniasis is diagnosed by NAAT on a vaginal swab or urine.

Herpes is diagnosed by swabbing an active lesion, which is why it is worth being seen while a sore is present rather than waiting for it to heal.

No test requires a pelvic exam unless you have symptoms that call for one. Nothing about the process is painful.

Treatment, infection by infection

Chlamydia. Doxycycline 100 mg twice daily for seven days is now first-line. This is a change from older guidance that used a single dose of azithromycin. Doxycycline cures the infection more reliably, particularly rectal infection, and it is what current CDC guidance recommends. Azithromycin remains an option in pregnancy, where doxycycline is avoided.

Gonorrhea. A single intramuscular injection of ceftriaxone. The dose was increased and the second oral drug removed from the regimen in the 2021 CDC update, in response to growing resistance. Gonorrhea has developed resistance to nearly every drug we have used against it, which is why oral regimens are no longer recommended and why a completed course matters.

Trichomoniasis. Metronidazole. For women, the current recommendation is 500 mg twice daily for seven days rather than the older single 2-gram dose, which was less effective.

Syphilis. Benzathine penicillin G by injection. One dose for early syphilis; three weekly doses for late or unknown-duration disease. Penicillin is the only treatment adequate in pregnancy — if you are pregnant and allergic, the answer is desensitization, not a substitute drug.

Herpes. Not curable, but very manageable. Antivirals — acyclovir, valacyclovir, famciclovir — shorten outbreaks when taken episodically, and daily suppressive therapy reduces the frequency of outbreaks and substantially lowers the chance of transmitting the virus to a partner. Most people with herpes have far less trouble with it than they expected on the day of diagnosis.

HIV. Treated with antiretroviral therapy, usually a single daily pill. Treatment that keeps the virus undetectable means it cannot be transmitted sexually. HIV care is managed with an infectious disease specialist, and we coordinate the referral.

HPV. There is no treatment for the virus itself. What we treat is what it causes — genital warts, and abnormal cervical cells found on screening. The HPV vaccine prevents the strains responsible for most cervical cancers and is recommended through age 26, and through 45 for some adults after a conversation about whether it is likely to help you.

Partners

Treating you and not your partner accomplishes very little. You will be reinfected, usually within weeks.

Every recent sexual partner — generally within the last 60 days, or the most recent partner if it has been longer — needs testing and treatment. In Illinois, expedited partner therapy is legal for chlamydia and gonorrhea, which means we can give you medication or a prescription to pass along to a partner who cannot easily get in to be seen. It is not a substitute for their own evaluation, but it is much better than nothing, and it interrupts the cycle of reinfection.

Avoid sex for seven days after a single-dose treatment, or until you have finished a seven-day course and any symptoms have resolved.

Retesting at three months

After treatment for chlamydia, gonorrhea, or trichomoniasis, come back for a repeat test about three months later. This is not a test of cure — the treatments work. It is because reinfection from an untreated partner or a new partner is common, and the three-month test catches it before it causes damage.

Prevention

Condoms reduce transmission of every STI substantially and are the only contraceptive method that does so. They are imperfect against infections spread by skin contact outside the covered area, such as herpes, syphilis, and HPV, but they help considerably even there.

Vaccination. HPV and hepatitis B are both vaccine-preventable. If you have not had either series, that is a straightforward thing to fix.

PrEP — pre-exposure prophylaxis — is a daily pill, or in some cases an injection every two months, that is highly effective at preventing HIV. It is appropriate for anyone with ongoing risk of HIV exposure, and asking about it is not a statement about your life; it is a reasonable precaution.

Doxy-PEP is a newer strategy: a single 200 mg dose of doxycycline taken within 72 hours after sex. CDC guidance recommends it for gay and bisexual men and transgender women who have had a bacterial STI in the past year. It reduces subsequent syphilis, chlamydia, and to a lesser degree gonorrhea. It is not currently recommended for cisgender women, because the one trial in that population did not show benefit.

Testing itself is preventive. Every infection found and treated is one that does not get passed on.

Coming in

Testing at our office is routine and unremarkable — the same conversation we have many times a week. Your results are protected health information, and nothing about your visit is shared with anyone without your permission. If you would like to be tested, or you have a symptom you want looked at, book an appointment or see our locations. If you want to know more about the physician you would be seeing, here is Dr. Alshahrour.

Related reading you may find useful: birth control options, routine check-ups and what they include, and our full range of services.

Medical disclaimer

This article is for general education and does not replace individual medical advice. Screening intervals, testing choices, and treatment regimens depend on your history, your anatomy, whether you are pregnant, allergies, and current public health guidance, which changes. Do not start, stop, or substitute any medication on the basis of this article. If you think you have been exposed to an STI, or you have symptoms, see a clinician for evaluation.