This article is the fourth part of a Natural Womanhood series on teen sex.
If you’ve ever wondered how big the sexually transmitted infection (STI) (or sexually transmitted disease (STD)) problem is in the United States—especially for teens—the stats speak for themselves. According to the CDC, “More than half of the nearly 20 million new sexually transmitted infections reported in 2020 were among young people (aged 15–24).” That’s more than 10 million high school and college-aged youth exposed to pathogens that can cause lasting harm to their health and future relationships. And it’s especially jarring to note that this figure is being reached by a population that is actually having less sex than the generation before it.
Although sexually transmitted infection prevention programs for teens focus heavily on promoting condom use, the CDC’s Youth Risk Behavior (YRB) survey found that less than half of sexually active high school students used a condom the last time they had sex. But does condom use (or lack thereof) really tell the whole story? Why are 15–24 year olds bearing so much of the burden of STDs in the United States?
Two reasons young adults are more susceptible to STDs
#1 Young adults are more prone to risky behavior in general
The teen years are a time of growth, maturation, and brain development. The prefrontal cortex of the brain–the region responsible for executive functioning skills like impulse control, planning ahead, and adapting to new circumstances—is still a work-in-progress until around age 25. While these skills can be practiced and learned, many teens struggle with thinking long-term and are more likely to make risky decisions as a result. Alcohol can further exacerbate difficulty in making good decisions, and the YRB survey found that 23% of high school students drank alcohol and 11% had engaged in binge drinking.
In a 2018 article from the Journal of Early Adolescence, researchers found that the younger a person was when they started engaging in sexual activity, the more likely they were to have had 2 or more sexual partners in the past year and, for females, the more likely they were to have had an STI in the past year .
Perhaps even more concerning is the increased risk sexually active teens face of experiencing sexual violence. The YRB found that “about 1 in 12 [high school students] experienced sexual dating violence” within 12 months of the survey. The risk of sexual violence increases 3-4 times for college-aged women (ages 18–24).
#2 Adolescent women are biologically more at risk of infection
With STDs, whether or not an exposure to a pathogen results in an infection is due in part to the maturity of the cervix. The cervix is composed of different types of cells: namely, columnar epithelial cells and squamous epithelial cells. The part of the ectocervix (the outer portion of the cervix) lined with columnar epithelium is referred to as ectopy . Ectopy is important because these types of cells are thin, fragile, and closely connected to nearby blood vessels, making the area prone to infection. As the cervix matures during and after puberty, the cells of the cervix transform. Most adult women have little to no ectopy and are therefore more resistant to STIs.
As we’ve discussed previously in our FAM Basics series, the hormone fluctuations that make up a normal menstrual cycle are important for the maturation of the cervix. Hormonal contraception blocks the natural ebb and flow of reproductive hormones and can prolong this stage of increased cervical vulnerability to infection .
STDs in the teen years can lead to other problems
STDs in and of themselves are no laughing matter. Viral STDs like herpes and human papilloma virus (HPV) can be lifelong infections. HPV that is not cleared by the immune system can lead to cervical cancer (you’ve likely seen an ad for Gardasil, a vaccine to prevent cervical cancer caused by certain strains of HPV). Bacterial STDs can be treated with antibiotics, but diseases like gonorrhea are becoming increasingly drug resistant and difficult to treat. Besides the infections themselves affecting the health and wellbeing of young people, STI complications like pelvic inflammatory disease (PID) and mental health issues can cause lasting harm.
Pelvic Inflammatory Disease (PID)
According to Cleveland Clinic, PID “is a serious infection in your uterus, fallopian tubes and/or ovaries.” Usually, this infection starts as an STI that then spreads through the reproductive tract. Cleveland Clinic states that over a million women in the U.S. are diagnosed with PID each year and the disease is most common in women between the ages of 15 and 25. Gonorrhea and chlamydia are the most common causes of PID, and can cause PID to develop within days or weeks of a woman becoming infected. The infection itself can be treated with antibiotics, but the resulting scar tissue remains and can cause infertility, ectopic pregnancy, and chronic pain.
Mental health problems
A recent PsychCentral article on the mental health impact of a STD diagnosis highlighted how sexual decisions impact the whole person. The article references a small study on people diagnosed with herpes simplex virus that found that 98% of survey participants reported experiencing symptoms of depression. While the article doesn’t explore the “why” behind this result, it’s easy to imagine how an STD diagnosis can become a dark cloud over someone. It can lead to distress over symptoms, concern over getting treatment, anxiety over how this will affect future relationships, guilt over inadvertently infecting a current or previous partner (or anger over being infected by a partner), feeling “punished” for a sexual decision in conflict with personal values, or feelings of hurt or betrayal. Since adolescent mental health is already considered a national crisis, teens need to avoid sexually transmitted infection exposure to protect themselves in both body and mind.
STDs are not a necessary part of becoming an adult
Sexually transmitted infections are so common that some people think of them as an inevitable fact of life, especially for teens. But they don’t have to be! Holding up the ideal of committed, long-term monogamous relationships, especially a healthy marriage, can help young adults protect and foster their whole-person health. Furthermore, encouraging and helping teens to understand their cycles can help young women to recognize their inherent dignity and make decisions that support a holistic approach to their reproductive health. Charting also requires self-discipline and thus provides an opportunity to practice executive functioning skills, so it’s good for both body and mind!
 Kugler KC, Vasilenko SA, Butera NM, Coffman DL. Long-term consequences of early sexual initiation on young adult health: A causal inference approach. J Early Adolesc. 2017 May;37(5):662-676. doi: 10.1177/0272431615620666. Epub 2015 Dec 9. PMID: 28529400; PMCID: PMC5435379.
 Anna-Barbara Moscicki, Yong Ma, Christie Holland, Sten H. Vermund, Cervical Ectopy in Adolescent Girls with and without Human Immunodeficiency Virus Infection, The Journal of Infectious Diseases, Volume 183, Issue 6, 15 March 2001, Pages 865–870, https://doi.org/10.1086/319261
 Hwang, Loris Y et al. “Factors that influence the rate of epithelial maturation in the cervix in healthy young women.” The Journal of adolescent health : official publication of the Society for Adolescent Medicine vol. 44,2 (2009): 103-110. doi:10.1016/j.jadohealth.2008.10.006