Chlamydia is one of the most common sexually transmitted infections (STIs) in the UK. Most people with chlamydia do not experience obvious symptoms, making it easy to carry the infection without knowing. Early testing is essential, especially after unprotected sex, to prevent serious complications and health risks. On this page, we explain the symptoms of chlamydia, how it is diagnosed, how long it can go unnoticed, and why regular sexual health checks are so important.
What Is Chlamydia?
Chlamydia is a bacterial infection caused by Chlamydia trachomatis. It spreads through unprotected vaginal, anal, or oral sex, as well as sharing sex toys that haven’t been cleaned or protected with a new condom between uses. Chlamydia can affect people of any gender. In women, it typically infects the cervix, rectum, and throat. In men, it can be found in the urethra, rectum, or throat. You can also get chlamydia from being exposed to infected vaginal fluid or semen.
Chlamydia is easily treated with antibiotics, but when left untreated it can lead to serious health problems, including infertility. Regular testing, especially if you’re sexually active or have changed sexual partners, is the best way to protect your sexual health.
How Does Chlamydia Spread?
Chlamydia spreads when infected vaginal fluid or semen comes into contact with the mouth, genital area, or anus during sexual activity. The main routes of chlamydia spread include:
- Unprotected vaginal, anal or oral sex
- Sharing sex toys without a new condom or without thoroughly cleaning the toys
- From a pregnant woman to her baby during childbirth (risking eye and lung infections in the newborn)
The infection can occur even if the infected person has no symptoms. Chlamydia is not spread through casual contact such as hugging, kissing, or sharing towels or toilets.
Most sexually active people can get chlamydia, and it can be passed between same-sex and different-sex partners.
Who Should Get Tested for Chlamydia?
You should consider a chlamydia test if you:
- Have had unprotected sex (vaginal, anal or oral) with a new or casual partner
- Have multiple sexual partners
- Share sex toys without washing or changing condoms between users
- Are under 25 and sexually active (annual screening is recommended)
- Have any symptoms of chlamydia or other sexually transmitted infections
- Are a man who has sex with men (higher risk of anal chlamydia)
- Are pregnant or planning a pregnancy
Free and confidential testing is widely available at a sexual health clinic in London, your GP surgery, or with a home test kit.
When Do Chlamydia Symptoms Start?
Most people experience no symptoms at all. If symptoms of chlamydia do appear, they can show 1 to 3 weeks after infection, but may develop months later, or come and go.
It is also possible to remain completely symptomless for years. This is why people often ask, “How long can you have chlamydia without knowing?” The answer: quite a long time, chlamydia can stay undetected and still cause health problems.
Chlamydia Symptoms in Women
Chlamydia symptoms in women are often mild, non-specific, or absent. When they do occur, they may include:
- Increased or unusual vaginal discharge
- Pain or burning sensation when urinating
- Pain during sex (sex pain)
- Bleeding between periods or after sex
- Lower abdominal pain
- Pain or discomfort in the rectum (if anal infection)
- Sore throat (after oral sex with infected partner)
- Watery or yellowish discharge from the rectum (anal chlamydia symptoms)
If left untreated, chlamydia infection in women can spread to the womb, ovaries, and fallopian tubes, causing pelvic inflammatory disease (PID), a major cause of ectopic pregnancy, chronic pelvic pain, and infertility.
Pregnant women with untreated chlamydia risk passing the infection to their baby during birth, which can lead to serious health problems like conjunctivitis or pneumonia in the newborn.
Chlamydia Symptoms in Men
Chlamydia symptoms in men may include:
- White, yellow, or cloudy discharge from the tip of the penis (unusual discharge)
- Burning or pain when urinating (peeing pain or burning sensation)
- Pain or swelling in the testicles (epididymitis)
- Discomfort or pain in the rectum, discharge, or bleeding (anal chlamydia symptoms)
- Sore throat (following oral sex with an infected partner)
- Redness or soreness at the tip of the penis (penis pain or penis burning)
As with women, many men have no obvious symptoms of chlamydia infection. Even without symptoms, the infection can cause inflammation in the testicles and tubes that carry sperm, with long-term complications including infertility if left untreated.
Chlamydia Symptoms in the Rectum, Throat, and Eyes
Rectal Chlamydia
People can get chlamydia in the rectum through:
- Unprotected anal sex
- Sharing sex toys with an infected person
- Spread from neighbouring genital infection
Symptoms may include pain, discharge, or feeling of fullness in the rectum, but rectal infections may also be asymptomatic.
Throat (Oral Chlamydia)
Chlamydia can infect the throat following oral sex with an infected partner. Most people do not notice symptoms, but some experience a sore throat.
Eye Infection (Chlamydial Conjunctivitis)
If chlamydia-infected semen or vaginal fluid enters the eyes, you may develop a watery discharge, redness, and irritation. This is more common in newborns but can affect adults. Untreated eye infections can cause permanent damage.
Do Chlamydia Symptoms Come and Go?
Yes, chlamydia symptoms can come and go. You may notice mild symptoms that disappear for weeks or months, leading you to believe you are healthy. However, the infection persists and can still cause serious complications.
How is Chlamydia Diagnosed?
To diagnose chlamydia, you need a test. Most commonly:
- Women provide a vaginal swab or urine sample
- Men provide a urine sample or urethral swab
- Rectal or throat swabs are used if there is risk from anal or oral sex
Testing is quick, simple, and confidential. You should get tested for chlamydia (and other STIs) after unprotected sex, or if you or a sexual partner are concerned.
Self-test kits for chlamydia are available for home use. Visit your local sexual health clinic, GP, or order a kit to your home. If you also want wider blood screening at the same visit, see our private blood tests in London.
How Long Can You Have Chlamydia Without Knowing?
You can have chlamydia for months or even years without any symptoms. This is why regular testing is so important for all sexually active people, especially those under 25, or with new or multiple partners.
Untreated chlamydia can cause serious complications, including pelvic inflammatory disease, ectopic pregnancy, infertility, and chronic pain.
What Are the Signs of Chlamydia?
The first signs of chlamydia can include:
- Painful urination
- Genital, rectal, or throat discharge
- Pain or swelling in testicles (men)
- Bleeding between periods (women)
- Unusual vaginal discharge
- Rectal discomfort
However, many people never notice any symptoms or signs of chlamydia.
How Long Does It Take for Chlamydia to Show Up?
Chlamydia symptoms can appear in 1 to 3 weeks after exposure but may take months to show, or remain absent entirely. You can’t know for sure without a chlamydia test. Test three weeks after any possible exposure, and consider retesting after three months if you have ongoing risk.
Can Chlamydia Be Misdiagnosed? What Else Can It Be?
Chlamydia shares symptoms with other sexually transmitted infections. For example, gonorrhoea, trichomoniasis, or urinary tract infections may cause similar discomfort. Only accurate testing can separate these conditions, and if you are concerned about HIV you can arrange private HIV testing in London.
What Happens if Chlamydia Is Left Untreated?
Leaving chlamydia untreated can cause:
- Pelvic inflammatory disease (PID) in women, affecting the womb and fallopian tubes
- Ectopic pregnancy and infertility
- In men, infection of the testicles, reduced sperm quality, and infertility
- Eye infections, arthritis, or the infection spreading to other organs
Prompt diagnosis and appropriate treatment prevent most complications.
How Do You Prevent Chlamydia?
To prevent chlamydia:
- Always use a new condom or dental dam for vaginal, oral, or anal sex
- Do not share sex toys—or if you do, clean them thoroughly and use a new condom for each person
- Get tested for chlamydia and other sexually transmitted infections regularly, especially if you change sexual partners
- Ensure that recent sexual partners are also tested and treated before resuming sex
- Discuss sexual health openly with new partners
Practising safe sex and regular sexual health checks lower your risk of all major sexually transmitted infection STIs.
Chlamydia Treatment: What to Expect
Chlamydia is easily treated with antibiotics, often as a single dose or a 7-day course. Common medications include doxycycline or azithromycin. You must avoid sexual contact until you and your partner(s) have finished treatment and for at least 7 days after.
A repeat test after 3 months is recommended to ensure you’re clear and not re-infected. Inform all recent sexual partners so they can receive treatment and prevent the infection returning.
For pregnant women, alternative antibiotics may be necessary. Always follow your healthcare provider’s guidance on medication and abstinence during treatment.
How Is Chlamydia Diagnosed at Broadgate GP?
At Broadgate GP in London, we offer confidential testing for chlamydia and other sexually transmitted infections. This may include a urine test, vaginal swab, or rectal/throat swabs, depending on your sexual history. Results are usually available within a few days, and our experienced team will support you through treatment, partner notification, follow-up testing, and sexual health education.
You can book an appointment directly with us or attend our sexual health clinic for testing and advice.
Risk Factors for Chlamydia Infection
Some groups have increased risk, including:
- Sexually active people under 25
- Those with multiple sexual partners
- People who have unprotected vaginal, oral or anal sex
- Men who have sex with men
- Individuals who have had chlamydia or another STI before
- Anyone sharing sex toys
Even if you had chlamydia previously and were treated, you can be re-infected.
Can You Get Chlamydia Without Intercourse?
Chlamydia is spread primarily by sexual contact: vaginal, oral or anal sex, or sex without a condom. You cannot catch it through everyday contact such as hugging, kissing, or sharing bathrooms. Rarely, mother-to-child transmission can occur during childbirth.
Long-Term Consequences of Untreated Chlamydia
Untreated chlamydia can cause serious, permanent damage:
- Chronic pelvic pain
- Infertility in both men and women
- Ectopic pregnancy (pregnancy occurring outside the womb)
- Eye and lung infections in babies born to infected mothers
- Increased risk of other sexually transmitted infections, including HIV
The best way to avoid these outcomes is regular STI testing and prompt, appropriate treatment.
What Should You Do If You Test Positive?
If you receive a positive chlamydia result:
- Complete the full course of antibiotics
- Inform all sexual partners from the last six months so they can get tested and treated
- Avoid sex until you, and your partner(s), have finished treatment
- Return for a follow-up test if advised
A healthcare provider at Broadgate GP can advise you on notifying partners confidentially, retesting, and any further steps to protect your sexual health.
When to Seek Advice from a Sexual Health Clinic
If you have any symptoms of chlamydia, have had unprotected sex with a new or multiple partners, are under 25, or are planning a pregnancy, make an appointment at a sexual health clinic. Testing for other STIs may also be recommended.
FAQs
What is one of the first signs of chlamydia?
Early symptoms can include pain or burning when urinating, unusual vaginal discharge or discharge from the penis. However, many people with chlamydia do not notice any symptoms at all.
Can you have chlamydia for years without knowing?
Yes. Chlamydia can remain unnoticed for a long time because many people experience no symptoms. It is not possible to tell how long you have had chlamydia from symptoms or a test alone.
How do I know if I have chlamydia?
The only reliable way to know is to have a chlamydia test. Symptoms can include discharge, pain when urinating, pelvic discomfort or testicular pain, but many infections cause no symptoms.
What can chlamydia be mistaken for?
Chlamydia symptoms can be similar to urinary tract infections, gonorrhoea and other sexually transmitted infections. Testing is needed to confirm the cause of your symptoms.
Does chlamydia go away with treatment?
Yes. Chlamydia can normally be cured with the appropriate antibiotics. It is important to complete the full course of treatment and follow your GP’s advice about when it is safe to have sex again.
How long does it take for chlamydia symptoms to appear?
If symptoms occur, they may appear within a few weeks of infection, although they can take longer and some people never develop noticeable symptoms. You should not wait for symptoms before arranging a test if you think you may have been exposed.
Is chlamydia contagious?
Yes. Chlamydia can be passed between sexual partners through vaginal, anal or oral sexual contact, even when the person with the infection has no symptoms.
How do I know if chlamydia has caused damage?
Possible signs of complications can include persistent pelvic pain, difficulty becoming pregnant or ongoing testicular pain. A GP can assess your symptoms and advise whether further investigation is required.
How quickly can I get chlamydia testing at Broadgate GP?
Broadgate GP offers discreet and confidential chlamydia testing at our City of London clinic, with same-day appointments often available. Most results are returned within a few days, depending on the tests carried out.
You can also arrange a broader STI screen alongside your chlamydia test through our sexual health clinic, including HIV testing where appropriate.
