Men's health

Chlamydia in Men: Scientific Overview

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Medically approved by Dr Earim Chaudry
Chief Medical Officer
iconLast updated 18th May 2021

In 30 seconds…

One of the most common STIs in the UK, chlamydia is a bacterial infection that’s passed on through contact with infected semen or vaginal fluid.

Symptoms of chlamydia in men include pain when you urinate, unusual discharge from the penis, and painful swollen testicles. However, up to 50% of men will have no symptoms at all.

It’s quick and easy to get tested for chlamydia, and the infection is usually simple to treat in its early stages, with a course of antibiotics.

Chlamydia is a sexually transmitted infection (STI), transmitted by the bacterium chlamydia trachomatis. It’s the most common sexually transmitted bacterial infection across the world, and it’s also one of the most common STIs in the UK. In 2018, nearly half the new STI diagnoses at sexual health services in England were diagnoses of chlamydia.

Chlamydia is most common among young people (under 25 years old), but you can become infected at any age. The long-term health implications of untreated chlamydia are particularly severe for women, because their fertility can be affected and it can cause Pelvic Inflammatory Disease. However, chlamydia can cause serious health problems for men too, if it’s not treated quickly.

Read on to find out more about how chlamydia affects men: How do men get chlamydia, what are the symptoms, how do you get tested, and how can chlamydia be treated? We’ll also look at the best ways to protect yourself from chlamydia.

How Do Men Get Chlamydia?

You can become infected with chlamydia by having unprotected vaginal, anal, or oral sex with an infected person. That is, when you don’t use a condom while engaging in vaginal or anal sex, or a dam when performing oral sex on a female partner.

However, any genital contact with someone infected with chlamydia can put you at risk of infection – it doesn’t have to be penetrative sex. Sharing sex toys can also transfer the infection, as you could be exposed to infected semen or vaginal fluid from the previous user. In addition, infected fluid entering your eye can also result in infection.

It’s important to note that you can’t become infected through casual contact such as hugging or kissing. And sharing items like towels, cutlery, or even toilet seats doesn’t place you at risk.

What are the Symptoms of Chlamydia in Men?

Many people who get infected with chlamydia don’t have any symptoms, and it’s estimated that this is the case for up to 50% of infected men.

Symptoms of chlamydia in men include:

  • Unusual discharge from the penis – which could be white, cloudy, or watery
  • Pain when you urinate, with a burning or itching sensation in your urethra
  • Pain and swelling in the testicles
  • Discomfort and discharge from your rectal area (if you’ve received anal sex)
  • Redness, pain, or discharge from your eyes (if they’ve come into contact with infected semen or vaginal fluid)

Chlamydia is usually easy to treat with a course of antibiotics (see below) but if the infection is left untreated it can lead to further health complications. These include:

  • Epididymitis: This is a painful inflammation of the testicles. It can be treated with antibiotics, but leaving it untreated can affect your fertility.
  • Sexually acquired reactive arthritis (SARA): SARA caused redness and swelling in your joints, particularly ankles, knees, and feet. There’s no cure for this but it usually clears up after a few months.

With this in mind, it’s important to get a test for chlamydia if you’re at all concerned you may have become infected.

How Do Men Get Tested for Chlamydia?

A chlamydia test is easy to get and completely painless. For men, it usually takes the form of urinating into a container, which is then sent for lab analysis. You can get a free test at a sexual health clinic, GUM (Genito-Urinary Medicine) clinic – which will typically provide a comprehensive STI screening to exclude other infections (e.g. HIV, syphilis, or gonorrhoea), or GP surgery. You can also buy a home testing kit.

In most cases, results are normally ready within 7–10 days, but if it’s highly likely you have chlamydia you might start treatment before the results come back.

It’s sensible to get a test if either you or your partner has symptoms of chlamydia (see above), or if a sexual partner tells you they have an STI. It’s also a good idea to get tested if you’ve had unprotected sex with a new partner, or your partner has had unprotected sex with someone else. Likewise, you might want to consider a test if you’ve had protected sex but the condom has split.

If you have a test for chlamydia less than 2 weeks after you had sex and the result is negative, you may be advised to repeat the test. This is because the infection is not always detected in its early stages.

How to Treat Chlamydia in Men

When the infection is caught early, chlamydia is easy to treat with a short course of antibiotics. Over 95% of people will be cured if they take the antibiotics correctly. The two types of antibiotics most commonly used to treat chlamydia are:

  • Azithromycin: Taken as 2–4 tablets all at once.
  • Doxycycline: Taken as 2 capsules each day for a week.

If your doctor is concerned about complications from chlamydia (see above), they might prescribe a longer course of antibiotics.

You’ll be advised not to have sex until you and your current sexual partner have finished treatment for chlamydia, or until a week after the 1-day treatment. It’s also important to contact any other sexual partners who could have been exposed to infection. A sexual health clinic can help you contact people anonymously, if that’s what you’d prefer.

How to Prevent Chlamydia in Men

It’s very common to become reinfected with chlamydia, as the body doesn’t build up immunity after the first infection. There is currently no vaccine for chlamydia, so the only way to protect yourself from becoming infected is to practise safe sex. This is particularly important if you have a new sexual partner and you aren’t aware of their sexual history.

Best practice is to use a condom during vaginal and anal sex, and while performing oral sex on a male partner. You can also use a dam when you perform oral sex on a female partner. The safest option is to avoid sharing sex toys, but if you do share them you can protect yourself by washing them or covering them with a new condom between uses.

Key Takeaways…

If you’re worried you may have chlamydia, it’s best to get tested as soon as possible. That way, you can get the treatment you need while the infection is still easily curable. You’ll also avoid passing chlamydia on to other partners. And, as ever, practising safe sex is the best way to protect yourself and others from becoming infected.


Meenakshi Malhotra, Seema Sood, Anjan Mukherjee, Sumathi Muralidhar and Manju Bala (2013). Genital Chlamydia trachomatis: An update:


Public Health England – Sexually transmitted infections and screening for chlamydia in England, 2018:

While we've ensured that everything you read on the Health Centre is medically reviewed and approved, information presented here is not intended to be a substitute for professional medical advice, diagnosis, or treatment. It should never be relied upon for specific medical advice. If you have any questions or concerns, please talk to your doctor.

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