Crush on a friend

I've known this girl for over 4 years now and we'll both be sophmores this year. The problem is that I've started developing a crush on her. This feeling has just been growing more over the summer, to the point where I feel my heart race when saying something as simple as happy birthday to her. I really like this girl but I really don't want to make things akward between us. Should I try asking her out, hope these feeling pass quickly, or if any of you have other advice it would be much appreciated.

Do you get any indication from her she might be feeling the same way? Does she smile at you? Look into your eyes? Find you funny? Wants to spend time with you? These would be indications. Otherwise, I would be careful unless you lose her as a friend.

If you really are close friends, the worst thing she can do is say no. I've been friends with a girl for almost 7 years now, a little under a year ago I started having a crush on her. I told her the truth about how I felt, she thanked me for being honest with her. We are still friends 4 months after I confessed to her, we are actually closer than we were before I told her. We've been able to be more open with each other, and have lunch every once in a while. If you honestly like her I'd say you should do it. If she says no, make sure you don't distance yourself from her because of her answer, that'll make her feel like you never really valued her as a friend. The pain of not being with someone is still better than the pain of never being able to be around them anymore.