For millions of girls growing up in evangelical Christianity, sexuality is a sin. Girls are sexual “stumbling blocks,” they’re told—a danger to the relationship between men and God.

Such is the way of the purity movement. Emerging out of white evangelicalism in the early 1990s, the conservative Christian movement—today promoted by both local churches and national organizations such as Focus on the Family and True Love Waits—emphasizes sexual purity and abstinence-only education. The cornerstone: If women remain virgins until the day they marry a man, they’re holy; if not, they’re damaged goods. To avoid the latter outcome, young adults are required to make promises—signified in the form of purity balls, rings, and pledges—to remain abstinent from puberty 'til “I do.”

After marriage, the metaphorical chastity belt unbuckles. But as writer Linda Kay Klein engrossingly details in her recently released book_,_ Pure: Inside the Movement that Shamed a Generation of Young Women and How I Broke Free, the psychological effects don’t stop there; they can follow women into their adult lives, leading to mental and physical side effects similar to symptoms of post-traumatic stress disorder.

In purity culture, both young men and women are taught that sex before marriage is wrong. But it’s teenage girls who end up most affected, Klein finds, because while boys are taught that their minds are a gateway to sin, women are taught that their bodies are. After years of being told that they’re responsible for not only their own purity, but the purity of the men and boys around them; and of associating sexual desire with depravity and shame, Klein writes, those feelings often haunt women’s relationships with their bodies for a lifetime.

Klein knows from personal experience. After realizing she couldn't be the woman the church wanted her to be, she left the evangelical community in the early 2000s. It was at that point, when she began considering having sex, that the symptoms started. “It began when I took the possibility of having sex and put it on the table,” Klein tells Broadly. “From that point on, sometimes it was my boyfriend and I being sexual that would make me have these breakdowns where I was in tears, scratching myself until I bled and ending up on the corner of the bed crying.”

Klein knew immediately that the reactions were linked to her religious upbringing, but assumed it was specific to her. “I never wondered where it came from, I just wondered why it was manifesting that way,” she says. “It couldn’t be that everyone who was taught these things were having these experiences, because surely I would have heard about it.”

Eventually, though, Klein realized that she wasn’t nearly alone. In 2006, she began compiling dozens of testimonies from childhood friends involved in the purity movement and found that they were all experiencing similar feelings of fear, shame, and anxiety in relationship to sex. “Based on our nightmares, panic attacks, and paranoia, one might think that my childhood friends and I had been to war,” writes Klein. “And in fact, we had. We went to war with ourselves, our own bodies, and our own sexual natures, all under the strict commandment of the church.”

Today, Klein considers the phenomenon an epidemic. When she first realized the scope and severity of what she was researching, she decided to quit her job—at the age of 26—and dedicate herself to learning more about the effects of purity culture. She went on to earn an interdisciplinary Master’s degree from New York University, for which she wrote a thesis on white American evangelicalism’s messaging toward girls that involved interviewing hundreds of current and past evangelicals about the impact of the purity movement on their lives. Eventually, those seeds of research grew into Pure.

A 12-year labor of love, the resulting book is an eye-opening blend of memoir, journalism, and cultural commentary that masterfully illustrates how religion, shame, and trauma can inform one another. Citing medical studies, she lays out that evangelical adolescents are the least likely “to expect sex to be pleasurable, and among the most likely to expect that having sex will make them feel guilty.” And in comparison to boys, Klein observes, girls are 92 percent more likely to feel shame—especially girls who are highly religious. For many women, like Klein, that shame can manifest in physical symptoms.

Klein observes and cites an expert who found that many women who grow up in purity culture and eventually begin having sex report experiencing an involuntary physical tightening of the vagina—also known as vaginismus—that is linked to a fear of penetrative sex and makes intercourse extremely painful. This could also be considered a symptom of Religious Trauma Syndrome (RTS), a diagnosis developed by Dr. Marlene Winell, a psychologist in San Francisco and author of Leaving the Fold: A Guide for Former Fundamentalists and Others Leaving Their Religion. According to Winell, as quoted by Klein, RTS is a condition “experienced by people who are struggling with leaving an authoritarian, dogmatic religion and coping with the damage of indoctrination.” The symptoms resemble those of PTSD, anxiety disorders, borderline personality disorders, and can result in depression, sexual difficulty, and negative views about the self.

Perhaps more convincing than the medical research and professionals that Klein cites, though, is the wealth of testimonies she gathers from women. One woman she spoke to described having years of awkward, uncomfortable sex with her husband until she began to feel overcome by such extreme exhaustion, she had difficulty getting out of bed. Another shared that after her first sexual experience, her body began to shake uncontrollably. In one extreme account, a woman said that feelings of panic and guilt flooded her mind “like a cloud of locusts” after an early sexual encounter. Soon after, orange-sized welts broke out on her stomach, arms, back, and breasts and it became difficult to breathe. After jumping into the shower to find relief, welts the size of both of her palms formed on her vagina. “I would say it’s the scariest thing I’ve ever seen in my life,” she told Klein. “I had no idea what was happening to me. My legs, my face, everything was bright red. It felt like I had absolutely no control over these horrific, nightmarish things that were happening to my body.” The woman was rushed to the emergency room, and though the doctors told her she went into anaphylactic shock, they couldn’t explain what caused it. While she knows something medical happened, she told Klein that's she is certain something spiritual happened to her as well—the result of what happens “when you tempt Satan.”

Pure is a thorough and focused study on the effects of the purity movement’s rhetoric on women and girls, but Klein stresses that her findings aren’t relevant only to religious conservatives. Rather, they represent an extreme microcosm of a broader culture of gendered sexual shaming to which we should all be paying attention.