Can a doctor tell if you have been using cocaine by looking inside your nose?

Doctors and Drug use: They may be very suspicious but would have other explanations. A good physician would feel free to ask if this is suspected. It is so much better not to lie about this. Especially to your physician. Medicine is not perfect, but addiction is a disease and your drug use, if it comes up, should be dealt with in a non-judgemental and respectful manner.