in Hamad u need to wait to much before getting an appointment.in private hospitals its difference,u can be walk in patient or apointment within short time.in big private hospitals u should come firstly to ER and there GP doctor will refer you to the specialist regarding ur complains and problems.If you know already the name of specialist u can try to go to him directly like walk in or most probably for an appointment.Also u should check list of hospitals covered by ur incurance.good luck.