Why Have I Had Muscle And Joints Pain For A Few Years?

I have had muscle and joint pains for a few years. Last month, after running to catch a plane I was unable to put weight on my right knee. After resting it a week, it was beginning to feel a little better. I then drove across town to bring my husband to an appointment. I drove for an hour and a half, and my problems started again. So ice and arthritis strength Tylenol and again I began to feel a little better when one morning I woke up with the left knee hurting.