Cutting can plague both men and women. Rates are particularly high among teen girls. One in every 200 girls between 13 and 19 years old, or one-half of one percent, cut themselves regularly.
People who cut usually start cutting in their young teens. Some continue to cut into adulthood. About one percent of the total U.S. population, or between 2 and 3 million people, exhibits some type of self-abusive behavior. That number includes those with eating disorders like anorexia, as well as those who self injure.
Often, teens that self-harm have an eating disorder. They may also have a history of abuse and suffer from depression or bipolar disorder. Many, however, are just regular kids with no other diagnosable problems.
Why do people cut?
Initially, cutting is not premeditated. It’s an impulse that they can’t control. Some people cut in order to cope with emotional issues, feelings of stress and pressure, or upsetting relationship problems. For others, cutting seems like a way of feeling powerful and easing the pain in their lives. Cutting might seem like the only way to find relief or express personal pain over relationships or rejection, but it is not.
The dangers of cutting
Cutters usually don't usually intend to hurt themselves permanently. When they start, they also don’t intend to continue. Both of those things can happen when they lose control of their behavior. Cutting can become compulsive behavior. The more a person does it, the more he or she feels the need to do it.
Sometimes cutters cut too deep, requiring stitches or hospitalization. Cuts can become infected if they are made with a dirty instrument.
How to help
You can't force a friend or loved one to stop. It doesn't help to get mad at a friend who cuts or reject that person. Recovery is entirely possible, but this person needs professional help. If you're truly concerned, suggest resources  that your friend can utilize.