Understanding Chlamydia -- the Basics

What Is Chlamydia?

Chlamydia, which strikes over 4 million Americans a year, is the most common bacterial sexually transmitted disease (STD) in the U.S. Scientists believe it's twice as common as gonorrhea and 30 times as common as syphilis.

The good news is that chlamydia is easily cured by antibiotics. The bad news is that 50% of women who contract the disease don't know they are infected and 30% develop serious complications such as damage to the fallopian tubes (the tubes that connect the ovaries to the uterus) caused by pelvic inflammatory disease, which may result in sterility. Damage to the fallopian tubes can also increase the risk of ectopic pregnancy (when the fertilized egg implants outside of the uterus). Untreated chlamydia in pregnancy may result in premature birth.

The infection can be passed on to an unborn child and cause serious complications. Babies born to infected mothers may suffer from pneumonia or conjunctivitis, an inflammation of membranes in the eye that may lead to blindness.

Fifty percent of infected men also have no symptoms. They may develop epididymitis or orchitis, an inflammation of the testicles that can cause sterility. Men can develop a chlamydia urethritis (and infection of the tube that drains urine from the bladder) and symptoms of discharge from their penis or burning when urinating.

What Causes Chlamydia?

Chlamydia is caused by the bacterium Chlamydia trachomatis. The disease is spread by oral, vaginal, or anal sex.


WebMD Medical Reference Reviewed by Sabrina Felson, MD on March 16, 2017



Mayo Clinic: "Chlamydia."

AMA: "Chlamydia Screening: A Routine Test."

CDC: "Chlamydia -- CDC Fact Sheet."

National Institutes of Allergy and Infectious Diseases: "Chlamydia."

Johns Hopkins Medicine. 


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