Emo does have to do with emotional. Mostly teens are emo. If their life is depressing, and they cut themselves (especially in wrists), they are considered emo. Just because someone wears black, dark make-up, has hair in their face, and wears skinny jeans does not make them emo. Emos are people too. They are not always depressed, they don't listen to all hardcore music, and they don't cut themselves 24/7. They do have lives. Emos usually only tell very close friends that they cut, they don't blab it to everyone to make everyone feel sorry for them. So if someone is telling everyone that they cut, then they are just doing that for pity.
A teenager that gets sad and cuts sometimes, which is considered emo.