Updated December 2014


Chlamydia is a sexually transmitted infection (STI) caused by the bacterium Chlamydia trachomatis.


Chlamydia can be passed on through unprotected oral, vaginal or anal sex from a person who is infected. It can sometimes cause eye infections when hands infected with anal, penile and vaginal fluids touch the eye. An infected person can pass on the infection at any time until he or she is properly treated with antibiotics.

Untreated chlamydia can live in the body for months or even years.

Signs and Symptoms

It can take two to six weeks or longer for symptoms to appear. More than 70 per cent of women and 50 per cent of men infected with chlamydia have no symptoms. However, they can still pass the infection on to their sexual partner(s) without knowing.

Women may have increased vaginal discharge or irritation. Other symptoms may include pain during urination, bleeding during or after sexual intercourse, abnormal spotting or bleeding between periods, pain in the lower abdomen or pain during sexual intercourse. The symptoms are sometimes mistaken for a bladder or vaginal infection.

Men may have a burning sensation when urinating, a discharge from the penis or itching around the urethra (opening to the penis). These symptoms may come and go.

Both men and women can get chlamydia in the throat from oral sex. This usually does not cause any symptoms. Chlamydia in the rectum can cause discharge, bleeding, anal itching, soreness or painful bowel movements. There can also be no symptoms.

Diagnosis and Tests

A doctor or nurse can take a sample by swabbing the infected area (cervix, urethra, rectum or throat). Urine testing is also commonly used to diagnose both men and women. Samples are then sent to the laboratory for testing.

In some cases, the doctor or nurse will advise a follow-up test to make sure the infection is cured. Follow-up testing by urine should be done three to four weeks after you have completed the treatment.


Untreated chlamydia in women may lead to a condition called pelvic inflammatory disease (PID). It is a serious infection of the lining of the uterus, the fallopian tubes and the ovaries. PID can cause chronic pelvic pain. Sometimes the fallopian tubes of a woman with PID are damaged and as a result, she may not be able to get pregnant or she may be at increased risk of having an ectopic pregnancy. Ectopic pregnancy is a life-threatening condition where the fertilized egg grows outside of the uterus, usually in the fallopian tubes. She will need treatment to stop the pregnancy.

Some men may develop swelling and pain in their testicles, a condition called epididymitis. It is also possible for men with untreated chlamydia to have blocked tubes so the sperm cannot pass, resulting in infertility.

Infants who are born to mothers with untreated chlamydia may get the infection as they pass through the birth canal. Infants may develop an eye infection or pneumonia.


Chlamydia is treated with antibiotic pills. Some of the most commonly used antibiotics include azithromycin, doxycycline, erythromycin and amoxicillin. It is important for a person diagnosed with chlamydia and their partner(s) to take all their medication as directed by their doctor or clinic.

Even if you do not have symptoms or the symptoms have disappeared, it is important to take all the pills to make sure that the infection is cured. Do not have sex while you and your partner(s) are on the medication and for seven days after you finish even with a condom.

Prevention/Self-care Tips

Here are a few important points to remember

  • Take all medication as prescribed by your healthcare provider or clinic.
  • Avoid sex for seven days after you and your sexual partner(s) have completed treatment. You can get re-infected every time you have sex with an untreated partner.
  • If you have an untreated STI like chlamydia, it is easier to get HIV from a person who has it.
  • It is possible to have more than one infection at a time, so it is important to be tested for other STIs and HIV.
  • Use condoms correctly every time you have sex to lower your chance of getting an STI.

Information for Sexual Partners

It is important to inform all of your sexual partners within the past 60 days so that they can be tested and treated. If you have not had sex in the past two months, then your last sexual partner should be tested and treated. Tell your partner(s) that having no symptoms does not mean there is no infection.

If you do not want to tell your partner(s), a public health nurse can notify them for you. Your name will be kept confidential.

More Information

Call the Sexual Health Infoline Ontario at 416-392-2437 or 1-800-668-2437

Safer sex: To reduce your risk of getting a sexually transmitted infection (STI), use a condom every time you have vaginal, anal or oral sex.