Infection rates of this common sexually transmitted disease are decreasing, but young women are still disproportionately affected. It is treated with antibiotics, but resistance is becoming a concern.

Chlamydia Overview

Reviewed: July 14, 2014

Chlamydia is a common sexually transmitted disease caused by bacteria. Chlamydia is the most frequently reported bacterial STD in the United States. You can get chlamydia during oral, vaginal, or anal sex with an infected partner. Both men and women can get it.

Chlamydia usually does not cause symptoms. If it does, you might notice a burning feeling when you urinate or abnormal discharge from your vagina or penis.

In both men and women, chlamydia can infect the urinary tract. In women, infection of the reproductive system can lead to pelvic inflammatory disease (PID). PID can cause infertility or serious problems with pregnancy. Babies born to infected mothers can get eye infections and pneumonia from chlamydia. In men, chlamydia can infect the epididymis, the tube that carries sperm. This can cause pain, fever, and, rarely, infertility.

Correct usage of latex condoms greatly reduces, but does not eliminate, the risk of catching or spreading chlamydia.

Experts recommend that sexually active women 25 and younger get a chlamydia test every year.

Chlamydia Symptoms

About 70 percent of chlamydial infections have no symptoms, thereby naming it the "silent" disease.

Symptoms may not appear until several weeks after sex with an infected partner. 

  • Women with symptoms may notice an abnormal vaginal discharge or a burning sensation upon urination.
  • Symptoms in men can include discharge from the penis, a burning sensation upon urination, or testicular pain and swelling.

Chlamydia infection can also cause inflammation of your rectum and lining of your eye (conjunctivitis or "pink eye"). The bacteria can infect your throat if you have oral sexual contact with an infected partner.

Even when chlamydia causes no symptoms, it can damage your reproductive system.


Chlamydia Causes

Chlamydia is caused by bacteria called Chlamydia trachomatis. Chlamydia can be transmitted by oral, vaginal, or anal sexual contact with an infected partner.

Chlamydia Diagnosis

Chlamydia is easily confused with gonorrhea because the symptoms of both diseases are similar and the diseases can occur at the same time.

The most reliable ways to find out whether the infection is chlamydia are through laboratory tests.

  • A healthcare provider may collect a sample of fluid from the vagina or penis and send it to a laboratory that will look for the bacteria.
  • Another test looks for the bacteria in a urine sample and does not require a pelvic exam or swabbing of the penis. Results are usually available within 24 hours.

Living With Chlamydia


To avoid transmission of sexually transmitted diseases, abstain from sexual contact or be in a long-term mutually monogamous relationship with a partner who has been tested and is not infected.

Correct usage of latex condoms greatly reduces, but does not eliminate, the risk of catching or spreading chlamydia.

Experts recommend that sexually active women 25 and younger get a chlamydia test every year. They also recommend an annual screening test for older women with risk factors for chlamydia (a new sex partner or many sex partners). In addition, all pregnant women should have a screening test for chlamydia.

If you have genital symptoms like burning while urinating or have a discharge, you should stop having sexual intercourse and see your healthcare provider immediately.


Chlamydia Treatments

Antibiotics will cure the infection. Chlamydia can be treated with antibiotics such as azithromycin (taken for one day) or doxycycline (taken for 7 days).

If you have chlamydia, you should:

  • Take all your medicine, even after symptoms disappear, for the amount of time prescribed
  • Go to your healthcare provider again if your symptoms do not disappear within 1 to 2 weeks after finishing all your medicine
  • Not have sex until your treatment is completed and successful
  • Tell your sex partners that you have chlamydia so they can be tested and treated, if necessary

These steps will help you avoid being reinfected with the bacteria. Repeated infections may increase the risks for reproductive complications.

Chlamydia Prognosis

Chlamydia can be cured with antibiotics. It is important that you take all of the medication your doctor prescribes to cure your infection. When taken properly it will stop the infection and could decrease your chances of having complications later on. Medication for chlamydia should not be shared with anyone.

Repeat infection with chlamydia is common. You should be tested again about three months after you are treated, even if your sex partner(s) was treated.


Twenty to forty percent of women with chlamydial infections, that are not adequately treated, may develop pelvic inflammatory disease (PID). PID can cause scarring of the fallopian tubes, which can block the tubes and prevent fertilization from taking place. 

  • Researchers estimate that more than 75,000 women each year become infertile because of PID.

In other cases, scarring may interfere with the passage of the fertilized egg to the uterus during pregnancy. When this happens, the egg may attach itself to the fallopian tube. This is called ectopic or tubal pregnancy. This very serious condition and can result in miscarriage and can cause death of the mother.

In men, untreated chlamydia may lead to pain or swelling in the scrotal area. This is a sign of inflammation of the epididymis. Though complications in men are rare, infection could cause pain, fever, and sterility.

Complications in newborns

A baby who is exposed to Chlamydia trachomatis bacteria in the birth canal during delivery may develop an eye infection or pneumonia. Symptoms of an eye infection, called conjunctivitis or "pink eye," include discharge in the eye and swollen eyelids and usually develop within the first 10 days of life.

Symptoms of pneumonia, including a cough that gets steadily worse and congestion, most often develop within 3 to 6 weeks of birth. Healthcare providers can treat both conditions with antibiotics.

Because of these risks to the newborn, many healthcare providers recommend all pregnant women get tested for chlamydia as part of their prenatal care.