A surprising number of Americans seek relief from emotional pain through self-injury or mutilation. They cut, burn or strike themselves, often hiding their wounds beneath their clothing. These actions are not suicide attempts, but rather efforts to cope with psychological trauma and stress, and sometimes physical or sexual abuse. Up to a quarter of teenagers and young adults have intentionally hurt themselves at least once. And mental health experts are worried the Internet is causing the phenomenon to spread. We’ll talk with psychologists who study and treat the condition and a young woman who has recovered.