Chlamydia is a bacterial infection that spreads through vaginal, anal and oral sex. It is one of the most common sexually transmitted infections (STIs) in New York City.

If left untreated, chlamydia can cause severe pain, infertility (inability to have children) and painful or swollen testicles. It can increase the risk of having a tubal (ectopic) pregnancy. Having chlamydia also makes it more likely to get or spread HIV.


Condoms and dental dams can prevent the spread of chlamydia. Having multiple partners increases your risk of getting STIs, including chlamydia.

Taking the medication doxycycline after sex can prevent STIs, including chlamydia, gonorrhea and syphilis. Taking doxycycline to prevent STIs is called Doxy PEP. Doxy PEP works best within 24 hours of sex.


Depending on the kinds of sex you have, your health care provider may test your urine or take samples from your cervix, penis, rectum, or throat. Be honest with your doctor about the kinds of sex you have.


Most people with chlamydia do not have symptoms. If symptoms occur, they can include:

  • Discharge from the vagina that is different than usual.
  • Bleeding between periods.
  • Discharge from the penis.
  • Pain or bleeding during or after sex.
  • Pain during urination.
  • Constipation.
  • Rectal pain, discharge or bleeding.


Chlamydia is treated with antibiotics. The full treatment is needed to clear the infection. Take all the medication even if you feel better.

You should be retested after three to four months to make sure that you did not get infected again.

Sex Partners

Your sex partner(s) also need to be treated so they do not develop serious health problems, re-infect you or pass the infection on to others. You should tell all of your sex partners from the previous two months about your infection so that they can see a health care provider.

You can also ask your health care provider about Expedited Partner Therapy (PDF) [Español], which lets your provider give you extra medicine or a prescription for your sex partners so they can be treated for chlamydia as soon as possible.

Chlamydia in Pregnancy

All pregnant people should be tested for chlamydia and other STIs, including HIV, as early as possible in pregnancy. Chlamydia can cause premature labor and low birthweight. It can also cause infections in the eyes and the lungs of the newborn baby.

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