Nausea

I have been having nausea on and off for months.  I asked my doctor about it in December and he didn't seem concerned about it.  I can go days and have no problem and then I have nausea so bad for three or four days that the smell of food and the thought of food make me throw up.  What could be causing the nausea?

[CHRISTYDRAKE]

Could be many things.  My son has been nauseated daily for over a year now, (prior to that it was frequent nausea).  He has been having tests done and they have now ruled out that the nausea is from the GI system.  They have concluded that his nausea is a neurological problem.  They believe it is part of migraines, even though he is not having them(or feeling them anyway).  He used to get migraines really bad.

So, nausea is hard to pin point because some many things can trigger it.