The Facts on Chlamydia

By Oliveira, Nancy 
March 21, 2017

The Facts on Chlamydia

Chlamydia is a disease that you can spread through sexual contact. It is caused by bacteria called Chlamydia trachomatis. According to the CDC, chlamydia is the most commonly reported sexually transmitted disease (STD) caused by bacteria. But many cases may be missed because most people don't know they have chlamydia. The infection has few symptoms in the early stages.

Who is at risk?

Anyone who has sex is at risk for chlamydia. Young adults are at particularly high risk. They may be less likely to use condoms during sexual intercourse. They may be more likely to have multiple sexual partners. Young women also may have cervical ectopy. Cervical ectopy means that the layer of cells lining the cervical canal extends to the outer layer of the cervix. This increases their risk for chlamydia. Some young adults may also not have access to STD prevention services.

Can chlamydia be prevented?

Practicing safe sex may help prevent chlamydia. Men and women can spread chlamydia by having unprotected sex. This includes vaginal, oral, or anal sex. You can reduce your risk by not having sex. Or if you do have sex, you can lower your risk by limiting the number of sexual partners you have. You can also lower your risk by using condoms and by using a dental dam during oral sex. Don't have sex with an infected person until he or she finishes treatment. If you are diagnosed with chlamydia, all of your sexual partners from the last 60 days should be tested. They should be treated for the infection if they test positive for it. Women are often reinfected if their sex partners aren’t treated.

Symptoms of chlamydia

Most people with chlamydia have no symptoms. An early sign of chlamydia in women is a mucous-like vaginal discharge. But women may not notice this because many women have different amounts of discharge from day to day. These are other symptoms that women may have:

  • Pain or burning when urinating

  • Abnormal vaginal discharge

  • Pain in the lower belly (abdomen) or lower back

  • Nausea

  • Fever

  • Bleeding between menstrual periods

  • Painful intercourse

Men with chlamydia may have discharge from the penis. They may also urinate often, having burning when they urinate, and have painful, swollen testicles.

Complications from chlamydia

Chlamydia can spread into the uterus and fallopian tubes if not treated. It can cause pelvic inflammatory disease (PID). Complications from PID are:

  • Long-term (chronic) pelvic pain

  • Infertility

  • Ectopic pregnancy (tubal pregnancy). Ectopic pregnancy happens when a fertilized egg implants in the fallopian tube instead of in the uterus. Ectopic pregnancies must be ended to save the mother's life. This usually requires surgery.

Chlamydia during pregnancy can affect the baby. These are some possible effects:

  • Premature birth

  • Low birth weight

  • Infections such as eye infection (conjunctivitis) and pneumonia

Women who have chlamydia are also at greater risk of getting HIV if they are exposed to the AIDS virus.

Men who have untreated chlamydia can get infections of the genital tract and prostate. Other complications of chlamydia in men include reactive arthritis and conjunctivitis. For men having sex with men, chlamydia can cause an infection of the rectal area.

Diagnosis and treatment

If you are diagnosed with chlamydia, you can quickly cure the disease with treatment. But most women and men with chlamydia have mild symptoms or none at all. That is why many people don’t know they have chlamydia.

Until recently, it was hard to diagnose chlamydia. This was because the tests were hard to do and the results were not reliable. A woman had to have a pelvic exam that let the healthcare provider take fluids from her cervix. Diagnosing a man involved taking a sample of fluid from his urethra. Better, less costly tests are now available. For example, one test looks for chlamydia bacteria in a urine sample. Many women now have chlamydia tests done on the same sample used to do the Pap test.

Healthcare providers treat chlamydia with antibiotics. The most common treatment is either a 7-day course of doxycycline or one dose of azithromycin.

All sex partners should be evaluated, tested, and treated. If you have chlamydia, don't have sexual intercourse until you and your sex partners have finished treatment. If not, you may get re-infected. Wait 1 week after taking the 1-dose azithromycin. You can resume having sex the day after finishing treatment with the 7-day course of doxycycline.

More screening is needed

Widespread screening is a good way to diagnose and treat chlamydia. The CDC and the Office of Population Affairs have started many screening programs. The CDC recommends screening every year for all sexually active women ages 25 and under. It also recommends yearly screenings for older women who have one or more risk factors. Risk factors include having more than one sex partner and not using a condom. Pregnant women should always be screened for chlamydia.



March 21, 2017


Clinical manifestations and diagnosis of Chlamydia trachomatis infections. UpToDate., Epidemiology of Chlamydia trachomatis infections. UpToDate., Screening for sexually transmitted infections. UpToDate., Treatment of Chlamydia trachomatis infection. UpToDate.

Reviewed By:  

Freeborn, Donna, PhD, CNM, FNP,Goodman, Howard, MD