STD Test: What Is Tested, How, and When to Get One

An STD test screens for sexually transmitted infections, most of which cause no symptoms for weeks or years while they spread and do damage. A full panel uses one blood draw for HIV, syphilis, and hepatitis, plus a urine sample or swab for chlamydia, gonorrhea, and trichomonas. Timing matters, because each infection has a window after exposure before a test can find it. Most adults who are sexually active with new or multiple partners should test at least yearly.

What a full panel covers

No single sample catches every infection, which is why a complete panel combines two.

Blood finds the infections that live in the bloodstream or leave antibodies there: HIV, with a fourth-generation test that detects both antigen and antibody; syphilis, with a pair of antibody tests; and hepatitis B and C. Herpes antibody testing is possible from blood too, but the CDC does not recommend it routinely in people without symptoms, because the test cannot say where or when an infection happened and false positives are common at low values. A swab of a sore is the better test when sores are present.

Urine or a swab finds the infections that live in the lining of the genitals, throat, or rectum: chlamydia, gonorrhea, and trichomonas. These use a molecular test called a NAAT, which is highly accurate. One detail people miss: a urine sample only checks the genital site. If you have had oral or receptive anal sex, the CDC advises asking for throat and rectal swabs, because an infection at those sites is missed by urine alone. Our full panel guide lists what to include.

Who should get an STD test, and how often

The CDC's testing recommendations are specific, and they are built around the fact that most infections are silent.

Everyone between 13 and 64 should be tested for HIV at least once, and everyone should be screened once for hepatitis B and C. Sexually active women under 25 should be tested for chlamydia and gonorrhea every year, as should women 25 and older with a new partner, multiple partners, or a partner with an infection. Sexually active gay and bisexual men should be tested for HIV, syphilis, chlamydia, and gonorrhea at least yearly, and every three to six months with multiple or anonymous partners, including throat and rectal sites. Pregnant people are tested for syphilis, HIV, and hepatitis B and C early in pregnancy, and some need chlamydia and gonorrhea testing too.

Outside those schedules, an STD test is warranted after any new partner, after a partner tells you they tested positive, when a condom breaks, and whenever symptoms appear: discharge, burning when urinating, sores, a rash, pelvic or testicular pain, or bleeding between periods.

The window period, and why it decides when to test

Every infection takes time to become detectable. Test too early and a negative result means nothing.

Chlamydia and gonorrhea can be found about one to two weeks after exposure. Trichomonas takes one to four weeks. Syphilis antibodies appear in three to six weeks. A fourth-generation HIV test detects most infections by 18 to 45 days, and a negative at 45 days is considered conclusive. Hepatitis B shows in three to six weeks; hepatitis C RNA within weeks, antibodies up to six months.

The practical rule: test for chlamydia and gonorrhea about two weeks after an exposure, and come back at six weeks for a panel that includes syphilis and HIV. If an HIV exposure was within the last 72 hours, that is a different conversation. Post-exposure prophylaxis can prevent infection if started in that window, and it is an urgent-care matter, not a lab test.

Where to get tested

Clinics, health departments, and primary care all offer STD testing, and many health departments offer it free. The trade-offs are privacy, convenience, and whether anyone looks at the result with you.

At-home collection is the other route. August's lab tests include single tests and full panels at one price that covers the draw. A phlebotomist comes to your home for the blood sample, with urine or swab collection as the panel requires, or you visit a nearby lab. Results post the next day in most cases, reactive screens are confirmed automatically, and a clinician reviews every result and can prescribe treatment through a consultation where appropriate. August Care members get up to 50 percent off next-day lab tests and a first consultation included.

Not sure whether you need a full panel or a single test? Describe your situation to August, a free AI health assistant, to help decide what to order. It is a starting point, not a diagnosis.

Reading your results

Non-reactive or negative means no infection was found, which is conclusive only if you tested after the window period closed. Reactive or positive on a screening test means a confirmatory test runs next, because screening tests are tuned to miss nothing and occasionally flag something that is not there. For HIV and syphilis, only a confirmed result is a diagnosis. Our guide to reading your results walks through each line of the report.

A positive result is treatable. Chlamydia, gonorrhea, trichomonas, and syphilis are cured with antibiotics. Hepatitis C is cured with a short course of tablets. HIV is managed with daily treatment that keeps the virus undetectable and, at that level, untransmittable to partners. Hepatitis B is controlled with medication.

Partners from the relevant period need to know and get tested. Most health departments offer anonymous partner notification if you would rather not have the conversation yourself. And the CDC advises retesting three months after treatment for chlamydia and gonorrhea, because reinfection from an untreated partner is common.

Privacy

Results are protected health information. They are stored in your private dashboard and discussed only with you. Laboratories are required by law to report certain confirmed infections, such as HIV and syphilis, to public health departments, as they are from any clinic or testing route; that data is used for partner services and statistics and is not shared with employers or family.