Hallucination

Hallucination is nothing but sensory perception which occurs in the absence of external stimuli. As for example we can call the followings;

Hearing voices when no one else is present. This is also called auditory hallucination.
Seeing something without the presence of that object. This is also called visual hallucination.
Smell something when there is nothing to produce the smell.  This is also called olfactory hallucination.
Types of Hallucinations:
*auditory hallucination
*visual hallucination
*olfactory hallucination
*deep sensation hallucination
*tactile hallucination
*Gustatory hallucination
Causes of Hallucination:
There are some physiological causes that can produce hallucination. Such as those occurring at the edge of the sleep are normal. They are called hypnogogic when falling asleep and hypnopompic on walking.
Schizophrenia
Delirium
Temporal lobe epilepsy
Hallucinating drugs such as LSD or Mescaine
Barbiturates withdrawal states
Diagnosis of Hallucination:
A case of hallucination can easily be diagnosed by assessing the nature, extent and time course of cognitive disturbance. This can also be diagnosed by assessing the underlying causes.
Treatment of Hallucination:
The treatment of hallucination is not so difficult. The treatment follows two principals. Number one, withdrawal of the precipitating factor and the number two is treatment of the underlying cause.