Chlamydia: Symptoms, Testing & Treatment What Every Sexually Active Person Should Know
As an OB/GYN, if there’s one sexually transmitted infection I wish my patients talked about more openly, it’s chlamydia (Chlamydia trachomatis).
Why? Because chlamydia often causes no symptoms. It is one of the most commonly diagnosed bacterial sexually transmitted infections (STIs), yet many people who have it have no idea they are carrying it.
Understanding how chlamydia is transmitted, when testing makes sense and how it is treated can help you make informed decisions about your sexual and reproductive health.
Why Chlamydia Often Goes Unnoticed
Chlamydia is a bacterial infection that primarily affects the body's mucous membranes. In women, it most commonly affects the cervix and urethra. In men, it frequently infects the urethra. Depending on sexual practices, infection can also occur in the rectum or throat.
One of the most important things to understand about chlamydia is that it frequently causes no symptoms. Around 70% of women and 50% of men have no or only minor symptoms.
Feeling completely well therefore doesn't necessarily mean that an infection isn't present.
What Are the Symptoms of Chlamydia?
When symptoms do occur, women may experience:
unusual vaginal discharge
burning or pain when urinating
bleeding between periods or after sex
lower abdominal or pelvic pain
deep pain during intercourse
Men may notice:
discharge from the penis
burning or pain when urinating
pain or swelling in the testicular area
Rectal infection can cause pain, discharge or bleeding, although it may also be completely asymptomatic. In rare cases, chlamydia can also trigger reactive arthritis, an inflammatory reaction affecting the joints.
Why Can Untreated Chlamydia Matter?
Most chlamydial infections can be treated effectively with antibiotics. However, an infection that remains undetected and untreated can sometimes lead to complications.
In women, chlamydia can ascend from the cervix into the uterus and fallopian tubes and contribute to pelvic inflammatory disease (PID).
PID can, in some cases, result in scarring of the fallopian tubes and increase the risk of reduced fertility, ectopic pregnancy, and chronic pelvic pain.
During pregnancy, chlamydia can also be transmitted to a baby during birth and may cause conjunctivitis or pneumonia in the newborn. This is why knowing when testing may be appropriate matters – even when you don't have symptoms.
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When Should You Get Tested for Chlamydia?
There isn't one testing schedule that is right for every sexually active person.
Whether testing is appropriate depends on your individual situation, including factors such as your age, symptoms, sexual practices, pregnancy, new or multiple sexual partners and possible exposure to an STI.
If you have changing or multiple sexual partners, have symptoms, know that a partner has tested positive, or are simply unsure about your personal risk, speak with your healthcare provider about whether testing makes sense for you.
Timing Matters
Testing immediately after a possible exposure may be too early. Modern tests are highly sensitive, but an infection may not be detectable immediately after transmission. If
testing is performed very soon after a possible exposure, your healthcare provider may therefore recommend repeating the test later.
This is also why a negative result needs to be interpreted in the context of when the exposure occurred.
How Is Chlamydia Tested?
The standard diagnostic method is a NAAT (Nucleic Acid Amplification Test), which detects genetic material from the bacterium.
For women, a vaginal swab – either self-collected or taken by a healthcare professional – is commonly used. For men, a first-catch urine sample is often suitable.
But there is one important detail that is easily overlooked:
The anatomical site of exposure matters.
Depending on your sexual practices and the type of exposure, a rectal swab or, in selected situations, a throat swab may also be appropriate.
This is one reason why there is no single “STI test” that is right for everyone.
Different infections require different tests, and the right sample may depend on where exposure occurred.
How Is Chlamydia Treated?
The good news is that chlamydia can usually be cured with appropriate antibiotic treatment.
For uncomplicated chlamydial infection in non-pregnant adults, doxycycline 100 mg twice daily for seven days is a commonly recommended first-line treatment and is particularly effective for rectal infection.
Treatment may differ in pregnancy or in other individual medical situations, so antibiotics should always be selected together with your healthcare provider.
It's also important not to take leftover antibiotics or medication prescribed for someone else. Appropriate diagnosis and treatment help ensure that the right infection is being treated with the right medication.
What About Sexual Partners?
If you've been diagnosed with chlamydia, recent sexual partners should be informed and evaluated so that testing and/or treatment can be arranged as appropriate.
This matters because otherwise the infection can be passed back and forth between partners, even when neither person has symptoms.
Your healthcare provider can advise you about which partners should be contacted and when it is safe to resume sexual activity.
Should I Get Tested Even If I Feel Fine?
Possibly – and this is where individual assessment matters. Chlamydia is a good example of why sexual health cannot always be assessed based on symptoms alone.
At the same time, not every asymptomatic person needs every available STI test.Your individual risk depends on your sexual history, partners, practices, timing and other circumstances.Good STI care is therefore not about testing everyone for everything. It is about understanding your personal situation and choosing the tests that are medically appropriate for you.
Questions About Chlamydia or STI Testing?
If you've started a new relationship, have symptoms, are planning a pregnancy, have had a possible exposure or simply want to understand your individual risk, professional advice can help you decide which tests are appropriate.
At Oh Yes Baby Yes, Johanna Janku, FMH Specialist in Gynecology and Obstetrics and Specialist in Sexual Medicine, provides evidence-based consultations on sexual health, STI testing, and preventive care.
Consultations are available in Zurich and online.
confidential · evidence-based
Related Reading
Many sexually transmitted infections can remain unnoticed for weeks, months, or even longer because they often cause no symptoms.
Learn why feeling healthy doesn't always mean you're infection-free, when STI testing may be appropriate, and why early diagnosis matters.
