Chlamydia is tested with a simple urine sample or a swab, and results typically come back within a few days. Most people don’t need a physical exam. The standard test detects the bacteria’s genetic material and is over 90% accurate across all sample types.
The Standard Test
The go-to method for chlamydia detection is called a nucleic acid amplification test, or NAAT. It works by finding tiny amounts of chlamydia DNA in your sample and copying it millions of times so it becomes detectable. This makes NAATs extremely sensitive: they catch about 94% of infections, with a specificity of 99%, meaning false positives are rare.
NAATs have largely replaced older methods like bacterial culture, which missed far more infections. For rectal chlamydia, for example, culture only detected about 27% of true infections, while modern NAATs caught 93%. The improvement is even more dramatic for throat infections, where culture detected 44% compared to 100% for the best-performing NAAT platforms.
What the Test Looks Like
For most people, testing involves one of two things: peeing in a cup or doing a swab. Which one you’ll use depends on your anatomy and where the infection might be.
- Urine sample: You provide a “first-void” sample, meaning the first part of your urine stream rather than midstream. This captures cells from the urethra that may carry the bacteria. Urine testing has about 95% sensitivity for chlamydia.
- Vaginal swab: A swab of the vaginal wall, which can be done by a clinician or by yourself. Self-collected vaginal swabs perform nearly as well as clinician-collected cervical swabs, with sensitivity around 92% to 98%.
- Rectal swab: If you’ve had receptive anal sex, a swab of the rectum is the only way to detect infection at that site. A urine test won’t catch it. Self-collected rectal swabs perform comparably to clinician-collected ones, so many clinics offer self-collection.
- Throat swab: Chlamydia can infect the throat through oral sex, though this is less common and often has no symptoms. Throat testing is less routinely recommended, but when a clinic tests the throat for gonorrhea, chlamydia results often come back automatically because many NAAT platforms test for both bacteria from a single swab.
The key point: you need to be tested at the body site where exposure happened. A urine test won’t detect a rectal or throat infection. If you’ve had both vaginal and anal sex, you may need samples from more than one site.
How Long to Wait After Exposure
Chlamydia doesn’t become detectable the moment you’re exposed. The bacteria need time to multiply enough for the test to pick them up. Testing too early can produce a false negative.
One week after exposure is enough time for most infections to show up on a NAAT. Waiting two weeks catches nearly all cases. If you test negative within the first week but still have reason to believe you were exposed, retesting after the two-week mark gives you the most reliable answer.
At-Home Testing Kits
Several companies now sell chlamydia test kits you can order online and use at home. These kits typically include a urine collection container or a vaginal swab, along with a prepaid mailer to send your sample to a lab. The lab still runs a standard NAAT on your sample, so the analysis itself is the same quality you’d get in a clinic.
The accuracy of self-collected samples holds up well against clinician-collected ones. In a meta-analysis of multiple studies, self-collected vaginal swabs had 92% sensitivity compared to clinician-collected cervical swabs, and in one study the sensitivity reached 98%. For men, self-collected urine had 88% sensitivity compared to clinician-collected urethral swabs. These numbers are slightly lower than clinician collection, but still reliable enough that self-collection is considered a reasonable alternative, especially when it removes a barrier to getting tested at all.
Who Should Get Tested and How Often
Chlamydia often causes no symptoms at all. Most people who have it don’t know. That’s why screening guidelines don’t wait for symptoms to appear.
The U.S. Preventive Services Task Force recommends annual chlamydia screening for all sexually active women 24 and younger. Women 25 and older should be screened if they have risk factors like a new sexual partner, more than one partner, a partner who has other partners, inconsistent condom use outside a monogamous relationship, a previous STI, or a history of exchanging sex for money or drugs.
For men, there’s no blanket screening recommendation from the USPSTF because the evidence on population-level benefits is still limited. However, many clinics do test men who have symptoms, who have a partner with chlamydia, or who are men who have sex with men. The CDC recommends at least annual screening for sexually active men who have sex with men, including rectal and throat sites based on sexual history.
There’s no fixed rule on how often to rescreen. A practical approach is to test again whenever your sexual history includes new risk factors since your last negative result. After treatment for a positive result, retesting at about three months is standard practice to check for reinfection.
Getting Your Results
Lab-based NAATs generally return results within one to five days, depending on the lab. The result is straightforward: positive or negative. A positive result means chlamydia DNA was detected in your sample. Because NAAT specificity is 99% or higher, a positive result is very reliable and doesn’t typically require a confirmatory test.
Rapid point-of-care tests do exist and can return results in under an hour, though they’re not yet widely available in most clinics. These rapid NAATs perform similarly to lab-based versions, with pooled sensitivity around 94% and specificity of 99%. As they become more common, same-day diagnosis and treatment will be possible in a single visit.
If you test positive, treatment is a short course of antibiotics. Partners from the previous 60 days should also be notified and tested. Because reinfection is common (your body doesn’t build lasting immunity to chlamydia), that three-month retest after treatment is important even if you feel fine.