Definition:
Hallucinations are false perceptions that an individual has within himself or herself that are not based in realty. Hallucinations can be present in any sensory modality, including auditory, visual, olfactory (smell), among others. For example, a person who is hallucinating may hear, see or smell things that are not there. The experience is quite real to the person and it is not uncommon for an individual to react as if the hallucination were real.
