Portuguese	English
o médico / a médica	the doctor
o consultório	the doctor's practice, the surgery
o posto de saúde	the local public health centre
o pronto-socorro	A&E, the emergency department
a consulta	the appointment, the consultation
a receita	the prescription
o atestado	a doctor's note, for work or university

To book, say Eu queria marcar uma consulta — I'd like to make an appointment (marcar — to book, to arrange).

Patients address a doctor as doutor or doutora: Bom dia, doutora. In writing it's Dr. and Dra. — Dra. Souza.