Littlle injury

I don't know where I got this, but I got knee injury. It is just a Minor one, every time I bend or apply pressure to my left knee, I feel the pain. That is why I am having a hard time to jump sometimes. What do you think is the cause?? as of now, I've got no answer. Maybe a strained ligament or something. They said that I should get a Patella braise or something to support it. Well, I hope I get answers soon so that I'll know what to do. The pain is growing.. Oh the pain.. The agony!!!