Chlamydia is one of the most common sexually transmitted infections in Singapore, and it often goes undetected because most people have no symptoms. Untreated chlamydia can lead to pelvic inflammatory disease, infertility, and increased HIV risk, so early testing matters.
Medically reviewed by Dr. Qiao Yufei, MD
This guide covers how chlamydia spreads, the signs and symptoms in men and women, how it is diagnosed and treated, and how you can protect yourself and your partners. Chlamydia is one of several conditions covered in our broader STDs in Singapore overview.
Chlamydia is a sexually transmitted infection caused by the bacterium Chlamydia trachomatis. Once transmitted, the bacterium multiplies in the genital tract, rectum, throat, or eyes and causes inflammation. Because most chlamydia infections are silent, many people pass the bacterium to partners without knowing they have it. Routine STI screening is the most reliable way to detect chlamydia early.
Chlamydia spreads through sexual contact with an infected person. Even when there are no visible symptoms, the bacterium can still be transmitted.
Some groups in Singapore are more vulnerable to chlamydia:
One of the trickiest aspects of chlamydia is that many infected people experience no symptoms at all. When symptoms do occur, they typically appear within days to three weeks of exposure, but can take several months.
Rectal pain, discharge, or bleeding can occur if the infection is in the rectum. Conjunctivitis can develop if infected fluids reach the eyes through hand contact.
If you or a partner notice any of these symptoms, or if you have had unprotected sex with a new or multiple partners, book a consultation and test. Early diagnosis prevents complications, protects others, and resolves the infection quickly with antibiotics.
Diagnosing chlamydia is simple, quick, and painless. At Mediway Medical Centre, testing usually involves one of:
Because chlamydia is often asymptomatic, regular STI screening is recommended. Annual testing is appropriate for sexually active adults under 25, those with new or multiple partners in the past year, and anyone in a group at higher risk.
Chlamydia is treated with antibiotics. The two most common regimens are:
Complete the entire course of antibiotics, even if symptoms resolve. Stopping early can leave the infection unresolved and contribute to antibiotic resistance.
Treatment does not give you immunity, and reinfection is common if a sexual partner is not treated at the same time.
Routine STI screening is one of the simplest ways to protect yourself, especially if you are in a higher-risk group. Schedule a follow-up test about four weeks after treatment to confirm the infection has cleared.
Open conversations about sexual health, recent partners, and STI status help both partners stay safe. If either of you tests positive, the other should also be tested and treated before resuming unprotected sex.
Untreated chlamydia can cause serious health problems:
Untreated chlamydia can cause reactive arthritis (Reiter's syndrome), affecting joints, eyes, and the urethra. It also increases the risk of contracting HIV and other STIs. Pregnant women with untreated chlamydia can pass the infection to their newborn, causing eye infections or pneumonia.
Chlamydia is primarily transmitted through sexual contact, including vaginal, anal, and oral sex with an infected person. The bacterium can be passed even when there are no symptoms.
Many people have no symptoms. When they appear, they usually do so within days to 3 weeks but can take several months.
In women: abnormal vaginal discharge, burning during urination, pain during intercourse, bleeding between periods, lower abdominal pain.
In men: penile discharge, burning during urination, testicular pain or swelling, pain during ejaculation.
In both: rectal pain, discharge, or bleeding if the infection is rectal; conjunctivitis if infected fluid reaches the eyes.
In women: pelvic inflammatory disease (PID), infertility, ectopic pregnancy, chronic pelvic pain.
In men: epididymitis (occasionally infertility), prostatitis.
In both: reactive arthritis (Reiter's syndrome) and increased risk of contracting HIV and other STIs.
Chlamydia is diagnosed via a urine test (analysed in the lab) or a swab test taken from the cervix, urethra, throat, or rectum. Testing is quick and painless. Early diagnosis allows prompt treatment and prevents transmission and complications.
Antibiotics are the standard treatment: azithromycin (single oral dose) or doxycycline (twice daily for 7 days). Complete the full course, avoid sexual activity for at least 7 days after completing treatment, and ensure recent partners are tested and treated. Repeat testing 3 months after treatment is recommended.
Yes. Use condoms consistently during vaginal, anal, and oral sex; have regular STI screening (especially if you are under 25 or have new or multiple partners); maintain a mutually monogamous relationship with a tested uninfected partner; and clean sex toys or use a fresh condom on them between partners.
References: CDC: Chlamydia fact sheet · WHO: STIs fact sheet · HealthHub Singapore
This page is for educational purposes only and does not constitute medical advice, diagnosis, or treatment. Consult a qualified healthcare professional for diagnosis and treatment of suspected chlamydia infection.