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Chlamydia Fact Sheet

What is chlamydia?

Chlamydia is a common bacterial infection that is sexually transmitted and often causes no symptoms. If not treated, chlamydia can damage reproductive organs and make it difficult for a woman to have a baby. Women age 25 and under who are sexually active should be tested for chlamydia at least once a year.

How do people get chlamydia?

People can get chlamydia through vaginal and anal sex. While less likely, it's also possible to get the disease through oral sex. A pregnant women can also give chlamydia to her baby.

Chlamydia is not passed through casual contact (like shaking hands) or toilet seats.

How common is chlamydia?

Over 1 million cases of chlamydia are reported in the U.S. each year, more than any other STD. Most cases are never reported, though, and experts think the actual number is closer to 3 million.

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What are the symptoms?

Symptoms can start within a few weeks after exposure to chlamydia, and may be minor. However, most people with chlamydia don't have symptoms, and don't know they have it.

Women may experience:

  • Unusual discharge or drip from the vagina.
  • Burning and pain when they urinate
  • If chlamydia spreads to the reproductive organs (like the fallopian tubes) a woman may have pain in the abdomen or lower back; pain during sex; fever; or bleeding between her periods.

Men may experience:

  • Discharge or drip from the penis
  • Burning when they urinate

Men or women who have anal sex can also get chlamydia, and may have pain, discharge, or even bleeding from the rectum.


There are several lab tests for chlamydia that are reliable. Some are done with urine (as simple as "pee in a cup"), while others take a swab from the penis or cervix. Ask your healthcare provider if you have questions about testing options.

All sexually active women age 25 and under should be tested at least once a year for chlamydia. Pregnant women and women over 25 with risk factors (a new partner, more than one partner, or unprotected sex) should also be tested. Anyone with genital symptoms (such as discharge, burning urination, or bleeding) should see their healthcare provider and be evaluated for STDs.


Chlamydia is easily cured with antibiotics. Treatment can be a single, one-time dose of an antibiotic or given over a course of one week.

To make sure chlamydia is cured:

  • All partners should be tested and treated
  • Take all of your medicine
  • Reinfection is common, so get tested again about three months after being treated (especially if you don't know if your partner was treated).

What happens if chlamydia is untreated?

In women, chlamydia that isn't treated may cause:

  • Pelvic Inflammatory Disease (PID). This can happen when the infection spreads to the uterus or fallopian tubes. If untreated, PID can cause chronic pelvic pain and tubal pregnancies. PID can even damage the reproductive organs and make it hard for a woman to have a baby. Chlamydia can also make it easier for women to contract an HIV infection.
  • It isn't common for men to have complications with chlamydia, but sometimes an untreated infection can lead to infection and pain with the tube that carries sperm from the testes. Rarely, this can make it difficult for a man to get a woman pregnant.

In pregnant women chlamydia can be passed to their babies, which can cause serious problems in a newborn (pneumonia and eye infections, for example). Pregnant women with chlamydia may also be more likely to have premature babies.

Reduce your risk

There are several things that can lower the risk of chlamydia and other STDs:

  • Use condoms or other latex barrier (such as a dental dam) for each sex act (oral, anal, and vaginal). A barrier should be put on before any sexual contact takes place.
  • Having sex with only one partner (who only has sex with you)
  • Appropriate testing and treatment. Talk with your healthcare provider to see what STD tests might be recommended for you.
  • Talk to your partner

It can be hard to tell a partner that you have gonorrhea, but keep in mind that your partner can have it and not know. Tell all recent sex partners so they can be tested.



National Institute of Allergy and Infectious Diseases