What is it?

How is it, that you can know that you're afraid of something but not be able to pin-point why? You can be genuinly fearful to the point of panic and tears and have no clue why you're scared or what you're scared of specifically. perhaps this is a sign that its a completley irrational fear. How do you get rid of it though? A fear is part of who you are. Its a part of your character. Who Knows.