What could be the cause of sudden dizziness ? my boyfriend has narcolepsy. meds: lilyfluoxitine. its when he gets up. not feeling nauseous though.

Several ideas: I am not sure whether the narcolepsy is related to the dizziness. I have 3 possibilities for the dizziness. Dizziness is a very non-specific symptom. If it is light headedness, this is a central problem and is related to either low blood pressure or autonomic dysfunction. If it is vertigo, then it may be bppv and will spontaneously resolve or with head excersizes. Rarely it is central (brain).