Our healthcare system is quite different from yours. Doctors work together in practices, and generally each person or family belongs to one practice. If I'm ill, I make an appointment to see my doctor at that practice. Usually, I see the same doctor all the time. But if she's on vacation, or she's busy all day, I can always see one of the others. Usually, my doctor will deal with whatever is wrong with me, but, if I've got a bad problem, she will send me to the hospital.