What it is
Chlamydia is a common bacterial sexually transmitted infection. Because it so often causes no symptoms, people can carry and pass it on without knowing.How care is approached
Safe care combines appropriate testing, an antibiotic when confirmed or clinically indicated, and clear advice on partners, abstinence and repeat testing.Testing
A doctor considers what testing is appropriate for the situation
described in the questionnaire.
Treatment when indicated
An antibiotic is considered when chlamydia is confirmed or clinically
indicated — the decision, and the specific medicine, is always made by
the reviewing doctor.
Partner and follow-up advice
Clear advice is given on informing partners, abstinence during
treatment, and repeat testing.
A doctor decides whether treatment is appropriate and what it should be —
never automatically, and never based on the questionnaire answers alone
without clinical review.
How Hi-Doctor handles it
The questionnaire covers symptoms, sexual health history, current medication and allergies — see how eligibility works and how safety checks run. Sexual health is offered as a one-off consultation; the cost is set out on pricing. Any medicine a doctor prescribes is paid separately at a pharmacy. See the full range of treatment areas Hi-Doctor covers.Related reading
- Sexual health consultation — how the one-off consultation is reviewed
- Urinary tract infection — another infection reviewed through the same consultation
- Safety and eligibility — where a remote consultation stops
- How a consultation works
Microbiology and treatment evidence
Chlamydia trachomatis is an obligate intracellular Gram-negative bacterium that infects columnar epithelial cells of the urethra, cervix, rectum and conjunctiva. Its unique biphasic life cycle alternates between infectious elementary bodies (EBs) and metabolically active reticulate bodies (RBs). EBs attach to host cells via heparan sulphate-mediated interactions and trigger internalisation; inside the inclusion, RBs replicate by binary fission before re-differentiating into EBs that lyse the host cell and spread to adjacent epithelium. The host inflammatory response — driven by cytokines including IL-8 and IFN-γ — produces the purulent discharge seen in symptomatic infection, but many infections elicit minimal or no clinical inflammation, allowing persistent carriage. A Cochrane meta-analysis of 14 randomised trials (2,715 participants) comparing antibiotic regimens found that, in men, doxycycline (twice daily for 7 days) resulted in a lower risk of microbiological failure than azithromycin (single-dose regimen) (RR 2.45, confidence interval 1.36 – 4.41; moderate-quality evidence) (PMID 30682211). For women, the difference in microbiological failure between the two regimens was uncertain due to limited data. Azithromycin was associated with slightly fewer adverse events overall. The clinical significance of these microbiological findings is that doxycycline is now preferred as first-line therapy in several European STI guidelines when adherence can be assured, though the single-dose azithromycin regimen remains useful in settings where adherence is uncertain. The reviewing doctor decides the appropriate antibiotic based on the individual presentation, allergy history, and ability to complete a multiday course.Diagnostic testing
The gold standard for diagnosis is nucleic acid amplification testing (NAAT) of a first-void urine specimen (in men) or a self-collected vulvovaginal swab (in women). NAAT targets cryptic plasmid DNA of C. trachomatis and has high sensitivity in symptomatic and asymptomatic individuals, which makes it suitable for screening programmes. Because the infection is frequently asymptomatic, testing is the only way to establish the diagnosis. In the consultation, the reviewing doctor considers whether a recent negative test, known partner treatment, or clinical presentation (symptomatic urethritis or cervicitis) justifies empirical treatment without a new NAAT result, or whether testing is needed first.Complications of untreated infection
Untreated chlamydial infection can ascend from the lower genital tract to cause pelvic inflammatory disease (PID) in women. Prospective cohort data indicate that symptomatic chlamydial infection is associated with an approximately 2.3-fold increased risk of PID (PMID 31504315). PID can lead to tubal factor infertility, ectopic pregnancy, and chronic pelvic pain. The risk increases with repeat infections. Ascending infection can also produce perihepatitis (Fitz-Hugh–Curtis syndrome) from spread of C. trachomatis across the peritoneal cavity, causing right-upper-quadrant pain. In men, untreated infection may cause epididymitis, prostatitis, and — rarely — reactive arthritis (Reiter’s syndrome), particularly in HLA-B27-positive individuals. These complications underscore why prompt diagnosis and treatment, coupled with partner notification and abstinence during treatment, are essential.Start a consultation
Sexual health consultation
Answer the sexual health questionnaire and a registered doctor reviews it.
They decide whether treatment is appropriate, which one, and at what dose —
and declining is a normal outcome. See what it costs
and how the review works.