Chlamydia is a sexually transmitted infection (STI) that can affect anyone. It's treatable, but it can lead to serious complications if treatment isn't sought.HealthlineSubscribeEverythingYouNeedtoKnowAboutChlamydiaInfectionMedicallyreviewedbyJillSeladi-Schulman,Ph.D.—WrittenbytheHealthlineEditorialTeam—UpdatedonFebruary26,2020PicturesCausesRiskfactorsInmenInwomenTreatmentHomeremediesDiagnosisUntreatedInthroatIneyeChlamydiaandgonorrheaPreventionWhatischlamydia?Chlamydiaisacommonsexuallytransmittedinfection(STI)causedbybacteria.Peoplewhohavechlamydiaoftendon’thaveoutwardsymptomsintheearlystages.Infact,about90percentofwomenand70percentofmenwiththeSTIhavenosymptoms.Butchlamydiacanstillcausehealthproblemslater.Untreatedchlamydiacancauseseriouscomplications,soit’simportanttogetregularscreeningsandtalkwithyourdoctororhealthcareproviderifyouhaveanyconcerns.ChlamydiapicturesChlamydiacancauseavaginaldischarge.Itmayresemblepusormucus.SymptomsofchlamydiamaybesimilartosymptomsofotherSTIs.SeephotosofsymptomscausedbydifferentSTIstounderstandthevisibleeffectstheseinfectionscanhave.ChlamydiacausesSexwithoutacondomandunprotectedoralsexarethemainwaysachlamydiainfectioncanbetransmitted.Butpenetrationdoesn’thavetooccurtocontractit.Touchinggenitalstogethermaytransmitthebacteria.Itcanalsobecontractedduringanalsex.Newbornbabiescanacquirechlamydiafromtheirmotherduringbirth.Mostprenataltestingincludesachlamydiatest,butitdoesn’thurttodouble-checkwithanOB-GYNduringthefirstprenatalcheckup.Achlamydiainfectionintheeyecanoccurthroughoralorgenitalcontactwiththeeyes,butthisisn’tcommon.Chlamydiacanalsobecontractedeveninsomeonewho’shadtheinfectiononcebeforeandsuccessfullytreatedit.Findoutmoreabouthowchlamydiaissharedbetweenindividuals.Howcommonischlamydia?In2017,morethan1.7millioncasesofchlamydiawerereportedtotheCentersforDiseaseControlandPrevention(CDC).However,manycasesgounreported,sotherealnumberofchlamydiainfectionseveryyearmaybecloserto3million.Menandwomencanbothgettheinfection,butmorecasesinwom