Why does my knee hurt all the time?

[LauraSoftball]

My knee keeps hurting a lot and I have no idea why. Sometimes it dosent hurt but most times it does and it hurts to walk on it. It dosent help that i fell on it in the school hallway. I love playing sports and running but its been hurting too much to do that. What should I do?

 

[traccy]

Yes see a doctor but it will heal slowly, or maybe not at all that depends on if it seriously damaged.