Chlamydia lab test: what to expect

Laboratory testing looks for chlamydia genetic material in a sample. Depending on the sexual contact and symptoms, the sample may be urine or a swab from the vagina, cervix, throat, or rectum. A urine sample does not check every body site. A negative result means the infection was not detected in that sample at that time; it may not answer questions about another exposed site or a very recent exposure. A positive result indicates infection at the sampled site and needs clinician-guided treatment.

Tell the clinician about the timing and type of exposure, symptoms, pregnancy, allergies, and medicines. Follow any sample instructions, including whether you should avoid urinating for a period before urine collection. Do not use antibiotics before testing unless a clinician advises it. If the result is positive, take the full prescribed course, inform recent partners through the service’s confidential process, and avoid sex until treatment instructions are complete. Ask whether repeat testing is needed.

Seek prompt review for pelvic or testicular pain, fever, pain during sex, unusual discharge, painful urination, or bleeding between periods after a possible exposure. Urgent assessment is needed for severe abdominal pain, fainting, heavy bleeding, or feeling acutely unwell, because complications can require rapid treatment.

Ask which body sites should be tested, when results are expected, whether other STI screening is suitable, what a negative result rules out, and when partners should be contacted.