Chlamydia is a common sexually transmissible infection (STI) caused by having unprotected sex (sex without a condom) with a person who is infected.

Chlamydia can affect both men and women and can occur in the cervix, penis, anus and occasionally the throat.


Many people will not have any symptoms so they may not know they have chlamydia. But even if you feel well it can still lead to health problems, and can also be passed on to someone else.

In women

When symptoms do occur in women they may notice any of the following:

  • an unusual vaginal discharge
  • a burning feeling when peeing
  • bleeding in-between periods or after sex
  • pain in the lower abdomen. 

These symptoms may go away without treatment – but health problems can still happen later on.

In men

Men may notice any of the following:

  • a whitish-yellow or watery discharge from the penis
  • a burning feeling when peeing
  • irritation or itching around the eye of the penis
  • painful, swollen epididymis or testicles.

Most anal infections also do not cause symptoms but some people notice pain or discharge. 

Infection in the throat does not cause any symptoms.

Other problems it can cause

In men

If chlamydia is untreated in men it can lead to swelling and pain in the epididymis or testicles which can lead to infertility.

In women

If chlamydia is untreated in women, the infection can spread up into the womb, fallopian tubes and other parts of the lower abdomen. 

This is known as pelvic inflammatory disease (PID). This can be painful and women may be quite sick and need to be admitted to hospital. 

PID can damage the tubes from the uterus to the ovaries which can lead to infertility. 

If a woman with damaged tubes gets pregnant, this pregnancy may be ‘ectopic’, or outside the uterus. 

Ectopic pregnancies are a medical emergency and usually require an operation. 

Infertility or ectopic pregnancy can even happen without the woman knowing that she had chlamydia in the past.

Babies born to mothers with chlamydia can develop eye and lung infections.

Having chlamydia can make it easier for a person to become infected with HIV or to pass HIV on to someone else.


If a male has discharge from his penis then a swab will be taken of the pus. A urine sample can also be used to test for chlamydia infection in men.

In women, the best way to test is to take a swab from the cervix. Women can also take a swab themselves from their vagina.

Swabs may also be taken from the anus and occasionally the throat.


Usually, treatment is with a single dose of antibiotic tablets.

However, women with PID or men with infection in the testes will need a longer course of treatment.

Sexual partners within the past 3 months need to be contacted so they can be tested and treated.

For more information contact the Centre for Disease Control's Clinic 34.

Last updated: 12 May 2016

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