A risk factor is something that increases your chances of getting a disease or condition.

Chlamydia is far more common in women than in men. The risk is highest among adolescents and young adults (generally up to age 25), who are more likely to take risks with their sexual behavior. African Americans have a higher prevalence of chlamydia than Caucasians. Other high-risk groups include American Indians, Native Alaskans, and Hispanics.

Chlamydia can't be seen, so you can't tell if someone has it. Since most people are unaware they are infected, chlamydia can get transmitted from person to person without your knowledge.

Other factors that may increase your chance of chlamydia include:

    
  • Multiple or frequent changes in sex partners
  • Inconsistent or incorrect condom use—latex condom use helps prevent the spread of sexually transmitted diseases (STDs)
  • A history of chlamydia or other STDs—reinfection is common and can lead to serious reproductive complications
  • Excessive alcohol or illegal drug use—increases the risk of risky sexual behavior
  • Men having sex with men
  • Another risk factor for women is cervical ectropion, a condition where cells from inside the cervix are on the outside. Although it usually doesn't cause problems, it can make you more susceptible to infection.