Chlamydia: testing, treatment and prevention

Chlamydia is a sexually transmitted bacterial infection that can be present with few or no symptoms.

It can affect the genitals, rectum or throat, depending on the type of sexual contact. Because someone may feel well, testing after a possible exposure is important. A positive result is treatable, and recent sexual partners need attention as part of preventing reinfection.

Many people do not notice symptoms. When chlamydia causes symptoms, painful urination is a very common presentation. Vaginal discharge, bleeding after sex, bleeding between periods, breakthrough bleeding and testicular pain are common presentations. Rectal infection may cause discomfort, discharge or bleeding, although it may also be silent.

The infection is passed through sexual contact with a person who has chlamydia, including vaginal, anal or oral sex. It is not passed by everyday contact such as sharing a toilet seat, towels, food or clothing. A person can transmit it even when they have no noticeable symptoms.

Without treatment, chlamydia can remain present and may be passed to partners. Symptoms, if they occur, can vary or settle without the infection having cleared. This is why testing and completing prescribed treatment matter even when discomfort improves.

Testing is sensible after sex without a barrier method, a new sexual partner, notification that a partner has an STI, or symptoms that could fit an infection. A clinician can advise which sites to test based on the kinds of sexual contact you have had.

Testing commonly uses a urine sample or a swab from the relevant body site. The appointment may also include discussion of other STI tests. Be open about the contact involved, as this helps ensure the right sample is collected; the conversation is confidential.

Chlamydia is treated with prescribed antibiotics. Take the medicine exactly as directed and do not share it with anyone. The clinician will explain when it is safe to resume sexual contact and whether follow-up testing is appropriate. Partners may need testing and treatment so that infection is not passed back and forth.

A diagnosis can bring embarrassment or worry, but it is a common reason for sexual health care. Write down questions before the appointment and ask how to notify partners confidentially. Avoid sexual contact until you have followed the clinician's advice about treatment and partner management.

Untreated infection can spread to reproductive organs and may lead to pelvic inflammatory disease. It can also cause inflammation around the testicles. Prompt testing and treatment reduce the chance that infection continues or causes further problems.

Using condoms or other barrier methods correctly during vaginal, anal and oral sex can reduce transmission. Regular STI testing and honest conversations with partners are useful when sexual circumstances change. Do not rely on the absence of symptoms to decide whether testing is needed.

A GP, sexual health clinic or gynaecology and urology service can arrange testing and treatment. Seek urgent medical care for severe lower abdominal pain, fever, vomiting, or sudden severe testicular pain.