I have an appointment with a nurse practitioner for a physical. what are some things that they won't be able to answer or do for me that my dr would?

It Depends: Most nps are very good at doing physicals and discussing routine check up questions. They are also usually good at knowing when something requires a higher md level of attention. They also can handle many common aliments just as competently as an md. The differences mostly come in when symptoms are difficult to diagnose or someone has a serious, rare condition.

Nothing, in general: Nurse practitioners (np's) have a nursing, rather than a medical background. One way to think of it is that nurse training is focused on the patient's response to health and illness, and np's add medical knowledge to that, whereas doctor training is focused on medical knowledge, sometimes adding training in patients' responses as well. They both can do good physicals, but may focus differently.