Chlamydia (full name Chlamydia trachomatis) is a bacterial STI.

In men chlamydia infects the urethra (tube inside the penis).

In women chlamydia infects the urethra and cervix (neck of the uterus). It can also infect the rectum and sometimes the eyes and throat.


Chlamydia is transmitted through:

  • Unprotected vaginal or anal sex
  • Sometimes chlamydia can be transmitted through oral sex.
  • Chlamydia can also be transmitted from mother to baby during childbirth. The baby may develop an eye or lung infection as a result.


Using condoms and lube when you have sex provides the best protection but it is not 100% effective.

Washing your hands with soap and water immediately after sex can also help prevent transmission, especially if having sex with multiple partners at the same time.

Signs and Symptoms

Both men and women often do not have any symptoms.

In women, symptoms, can include:

  • unusual vaginal discharge
  • unusual vaginal bleeding (especially after sex)
  • lower abdominal pain (including pain during sex)
  • pain or discomfort when urinating.

In men, symptoms, can include

  • soreness or redness at the opening of the penis
  • discomfort when urinating
  • clear or whitish discharge from the penis.



The best way to find out if you have chlamydia is to have a test.

For women, a full check-up is usually needed but sometimes just a urine sample is enough.

For men, a urine sample is needed.

If rectal infection is a possibility , a swab is taken from just inside the anus.

Having a swab taken is not painful although it may be uncomfortable.


Chlamydia is easily treated with antibiotics. Standard treatment takes seven days but single-dose treatment is also available. It is very important to finish all the antibiotics, otherwise the infection may not be properly treated and a drug-resistant strain can develop. A follow up check will confirm that the chlamydia has gone.

If you’re HIV + and have chlamydia…

If diagnosed early, chlamydia is easily treatable for people living with HIV. However, if it’s left untreated chlamydia can also increase the risk of HIV being passed on.

Why should I worry about getting chlamydia?

Women: If left untreated, chlamydia may lead to pelvic inflammatory disease (PID). This is when the reproductive organs, situated in the pelvis, become inflamed. PID can cause ectopic pregnancies (the pregnancy develops in the fallopian tubes instead of the uterus), infertility and chronic pelvic pain.

Men: If not treated, chlamydia can spread to the testicles, leading to pain and swelling. Chlamydia may occasionally cause infertility in men. Sometimes chlamydia may trigger a condition called Reiter’s disease (or ‘sexually acquired reactive arthritis’) which causes inflammation of the eyes, skin and joints.

Babies: Chlamydia can be passed from mother to baby during birth. The baby can develop eye and ear infections, or pneumonia.

[DO1]Do women need to be concerned if they’re using the antibiotics? Do they reduce the effectiveness of the pill?