Re: what does it mean when your breasts are very tender and hurt.

Breast tenderness.

There can be many reasons for breast tenderness, depending on the 
situation, i.e., age, menstrual status,medicines being taken, and if the 
tenderness is recent, cyclical, or constant.

You are grade 10-12, so at that age it may be due to hormonal influences 
from the ovaries which are starting to be more active.