I am 14 years old(girl) and I have a bruise on my back it is pretty much gone now.

When you had your blood tests did the doctor say you're underweight for your height? It sounds like you really need to eat more but given the different issues you're worried about I recommend getting help from a health professional rather than from the internet.

Bruises come and go. That's normal.
I hit and bang myself all the time. I can usually trace it back to an action, if I really think about it.

What did the Dr. say about your weight?

the problem is that all suggestions and questions you will get with this post is that they will only be answered with and through your doctor.

My first guess is anemia
But again... gotta ask the doctor.

As for bruising.. there are many possibilities. And if you are starving yourself, well.. there is the issue. You can have low calorie, weight maintaining eating habits with out starving your body and making it behave like that..

Eating and drinking are vital for your health and much, much more important than having an appetite or not. All other things in your life depend on it, including good mental health. When that gets included, you may feel you lose control so make sure that that never will happen, by simply eating when everybody else eats (and drinks and sleeps).

I have to add here that I worry about our poster. Bruising is a symptom doctors pay attention to.

Please keep posting...

love, do you have any kind of access to some kind of main medical center care?

Everyone who lives, dies... For the young, that is not the real problem... You must steel yourself to the very real possibility that you might live a long time before the real reality of death occurs, and that means preparing yourself for life as though it is actually going to happen, and that you will not drop dead for no apparant reason... It is hard to imagine, but just as an infant gives birth to himself, or herself by the way it moves in the birth canal, so you must force yourself into adulthood with the greatest act of courage.... You must accept it, and use the next few years to prepare yourself to the utmost...