Chlamydia is a common sexually transmitted bacterial infection (STI) which is usually passed on by having unprotected sex. It’s also known as chlamydia trachomatis.

By Wallace Health I Medically reviewed by Adrian Roberts.
Page last reviewed: October 2018 I Next review due: October 2021

What is chlamydia?

Chlamydia affects men and women. It’s the most common STI in the UK, especially among sexually active women under 25.

In women, it can affect the area around the cervix (entrance to the womb) or the urethra (the tube between the bladder and the outside of the body). In men, it usually affects the urethra. However, in many cases there are no symptoms.

It’s easy to treat with antibiotics. It can cause other health problems if it’s not treated early on, including pelvic inflammatory disease, reactive arthritis and infertility.

How to tell if you have chlamydia

You may not have any symptoms of chlamydia – many people don’t know they have it. It’s a good idea to get tested every year if you’re sexually active and under 25, or more often if you have more than one partner.

The most common symptoms are pain in your genitals and/or pain when you urinate.

Chlamydia symptoms in men include discharge from your penis, as well as painful or swollen testicles. It may be uncomfortable pr painful to have sex. Chlamydia symptoms in women include vaginal discharge, pain in your pelvis and abnormal bleeding, including after sex.

If your back passage is infected, there may be bleeding or anal discharge. Chlamydia can also affect your eyes or nose.

If you have unusual discharge or pain (especially when you urinate), or if your partner has been diagnosed with chlamydia, you should ask your GP for advice as soon as possible or visit a sexual health clinic.

Talk to your doctor if you’re concerned about symptoms

You can book an appointment with a Spire private GP today.

Diagnosis and tests for chlamydia

Getting a chlamydia test is easy. It’s a good idea to get tested regularly, especially if you have more than one sexual partner, sometimes have unprotected sex, or if you’re planning to become pregnant.

Your GP may refer you to a sexual health clinic. They may test for more than one type of STI. For women, your doctor or nurse will take a sample of the discharge from inside the vagina or anus, using a small cotton bud. In some cases, they can give you a kit so that you can do this at home. For men, it can be diagnosed from a urine test.

In most cases, you’ll be given your results after about a week. If the test is negative, you might have another test about a fortnight later because it can be difficult to detect during the first two weeks. You may be offered a repeat test after three to six months if you needed treatment, to check you haven’t been re-infected.

Causes of chlamydia

Chlamydia is caused by bacteria called chlamydia trachomatis. You’re most at risk if:

  • You have unprotected sex with someone who already has the infection
  • You’ve had more than one sexual partner during the past year
  • You’ve been infected with another STI such as HIV or gonorrhoea

Common treatments for chlamydia

The usual treatment is antibiotics for up to 10 days. You should avoid having sex during this time. It’s also important to let your partner(s) know so that they can get treatment too and avoid passing it on.




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