doctor前边可以加冠词a，例如：

1、You'd better see a doctor about that cough.你最好找医生治治你的咳嗽。

2、I tried to persuade her to see a doctor.我极力劝她去看医生。

3、Don't just stand there， man ─ get a doctor!你这家伙，别只是站着——赶紧去找医生呀！