My friend needs help! please I need some advice

Hey, so I'm nearly fourteen, and me and my best friend (who I know for about three years) were really good friends, and did normal stuff like teens do and everything and then one day my friend told me she cut her wrists. The scrathes weren't deep or anything so she wasn't trying to kill herself obviously. That was about six months ago. From then on it was usual for her to have huge scars or little scratches on her wrists.
A few days ago she told me that she actually got drank with someone, and then, which shocked me the most that she hasn't eaten anything for the past few days. Later I discovered that the last time she hasn't eaten anything, she lasted for two weeks (!!!!!!!!!), and then she fainted. She ended up in hospital, but she told me that neither her or her mom told the doctors about her not eating anything.
When I told few of my mates they joked about it and didn't take it seriously.
Anyway I have never seen her eat anything in school before, and when I asked her why she was doing this she said that it's not because she doesn't want to eat, but because she's not hungry and so she can't be bothered to eat. When I told her that if she doesn't do anything about this she might get ill and eventually die, she said she doesn't care.
I really don't know what to do, I sworn to secrecy but I know that I should tell someone. What kind of illness is it? And why is she doing it? Is it to attract attention to herself? Or does she really want to kill herself? How can we help her? please, give me your advice! Thanx

It could be Anorexia or some other disorder causing the lack of appetite. A cancer in or around the stomach, a bad ulcer, or a bacterial infection of the lungs could also kill the appetite. Usually it is socially motivated though. Skinny women get teased less. Skinny women are paid millions to walk runways with designer clothes. Let her know your worries, but only go over her head if it looks like her life is in danger or there is noticable harm being done to her body.

If she won't listen, then suggest to her parents that they look at their daughter's eating habits.

Self injury is a serios problem that affect many people especially teens. She needs help if she's doing this and also she needs to recognize she has a problem. It is already difficult to stop self injury and without the person's willingness it's impossible to solve it. Here is a link that talks about it... google self injury or self mutilation for more info. These type of problems are often accompanied with depression. http://www.coolnurse.com/self-injury.htm

OMG 0.0 first of all the illness is called depresstion and yes its a real thing she might be going through a hard time or mayjor peer pressure or she might have had some stuff happen in her past that not evan you know about 2nd im going to say that yes she is doing it 4 attention but not like how you think she may not want anyone to know about it only you because your her boyfriend but she maynot have been given the right kinda attention growing up or she just cant get her point across 3rd she may really not care if she does die it may be that she is tired of whats fake and just dosnt want to deal with things..so here is my advice to u ..if you need a pen and paper to remember go ahead lol..let her know that you luv her and care for her that you dont want anything to happen to her she already knows if she keeps up like this she is going to die so dont critazize her be there for her whenever she says she wansta die say if you die were would I be or if you die im going to die 2 because I cant live without you or evan say do you really want to leave me to and see me cry everyday because your not around it will take a lil to get it acoss to her that she is luved but it works be a good friend when ever she needs to talk always and I mean always no matter how mad you r at her always be there for her tell you will never leave her when ever she says something bad about herself be like who said that they are going to die in seven dayz just b there 4 her and luv her kk..if you need nemore advice just ask I would know how 2 help because my friend is doing the same for me --a friend