More than 40 percent of American children and teens experienced abuse in 2011, and one in 10 was physically injured.

All too often, the physical and emotional abuse of children is discovered after the fact. But what seems like an inconceivable horror to some is all too real for more than 40 percent of children under the age of 17 in the United States.

Every so often, a story like the harrowing escape of three young women from a home in Cleveland after a decade of abuse reminds the public just what can go on behind closed doors. More frequently, a story of bullying gone too far in school or online comes to light.

Because childhood exposure to violence, crime, and abuse can have serious ramifications later in life, it’s important that children receive as much help and support as possible after the fact and that doctors and caregivers have as complete a picture as possible of childhood trauma in the U.S.

Researchers from the University of New Hampshire have now updated the estimates and trends for childhood exposure to abuse and violence to better map the landscape of dangers facing American youth.

Consider this: Two out of every five children surveyed, or more than 40 percent, were physically assaulted in 2011. One in 10 children sustained an injury, and two percent experienced sexual assault or sexual abuse, though the rate was nearly 11 percent for girls ages 14 to 17. The results also show that more than 13 percent of children and teens repeatedly experienced abuse by a caregiver, including 3.7 percent who suffered physical harm.

These high rates of abuse call for “much more systematic, frequent, and intensive efforts to monitor the epidemiology of these problems,” the researchers wrote.

These numbers should be shocking, and study author David Finkelhor, Ph.D., hopes his findings will open up the public discourse about violence against children.

While groups often mobilize around single issues like bullying or date rape as a way to start organizations and obtain funding, those efforts only build awareness of a certain type of abuse, Finkelhor says. A more complete picture of childhood trauma is required.

The hope, says Finklehor, is that these findings sensitize caregivers, teachers, parents, and clinicians to the obstacles facing children today.

“[There is a] wide variety of violence, abuse, and crime that young people are exposed to and we need to pay attention to all of it, not just a small slice like bullying or sexual abuse,” he said in an interview with Healthline. “We hope this encourages physicians to screen kids for exposure and direct them to help.”

There’s ample evidence that serious consequences follow childhood exposure to abuse, including developmental difficulties, defiant behavior, and physical and mental health consequences, according to researchers from Duke University.

The researchers drew on a national sample of more than 4,500 children between the ages of 1 month and 17 years old. Children were initially interviewed over the phone and with their primary caregiver, and then, if they were over the age of 10, they were interviewed alone via phone. If they were under the age of 10, they were interviewed with a caregiver present to facilitate the interview.

While a telephone interview may seem indirect, the researchers reported that not only is telephone interviewing cost-effective, it also provides a comparable quality of information to in-person interviews. Because of the distance afforded by speaking over the phone, respondents also tend to feel more anonymous and safe than if they were talking with someone in person.

The survey researchers used covered six areas of general concern: sexual assault, child maltreatment, conventional crime, Internet victimization, peer and sibling victimization, and witnessing and indirect victimization.

Finkelhor says he was surprised to find that childhood abuse didn’t seem to increase during the recent economic downturn, which could have been one tragic side effect of a flailing economy.

Finkelhor and his team are well on their way to creating a complete picture of violence against children in the U.S. They “will continue to monitor trends and will have results for 2014 in another two years,” he said.