Marcos: Bom dia, doutor. Estou doente. Doutor: Onde dói? Marcos: As minhas pernas doem. Doutor: Tu tossiste ontem à noite? Marcos: Sim. Doutor: Tens gripe! Trata com o remédio verde em cima de minha mesa todo dia. Marcos: Obrigado. Adeus!
The doctor is treated with "doutor" ("doutora" would be the feminine). Sometimes with the name, but always with "doutor". ("Doutor Souza").
Note:
"Doctor" is also a away to show deference/reverence for the other's higher education and is not only used to qualify a medical doctor, for instance in addressing a lawyer (or any other doctorate). In this context professional titles are always used (Engineer, Architect, etc) if deference/reverence is intended, even amongst peers. It fallows the same social rules regarding "Dona" ("Don" is not used), "Senhor" or "Senhora" for those without special titles.
The regular verb "doer" (to feel pain or hurt), is defective. It just exists in two conjugations. Singular (dói) and plural (doem).
Now, it is time to learn some new words:
"Doer" (verb) / to hurt, (a) dor / pain
"Vomitar" (verb) / to vomit or to trow-up, (o) "vômito" / vomit
"Gripar" (verb), to have a gripe, (a) gripe / the flu