In general terms, the feeling of objects that do not exist in reality, is considered as hallucinations. It happens many times with us that we start assuming for something which is not real in actual, but we start taking it as it is affecting us and when this feeling gets stronger it turns to be hallucinations. It is nothing but an assumption of our brain. There can be several reasons that cause this disorder. In these causes, we can consider sleep deprivation or the influence of sensational stories or movies too that affect human brain.
Behind Hallucinations, there can be varied reasons. These reasons include over consumption of alcohol or the usage of drugs like LSD, Cocaine, Marijuana, PCP, Heroin, Amphetamines, Ketamine etc. Sometimes visual hallucinations develop due to dementia or delirium. The sleep disorders like epilepsy also cause this problem. Basically, epilepsy involves temporal lobe which is a part of brain and thus, it develops odor hallucinations in patients. Some children, who suffer from constant fever, also start hallucinated. Various psychiatric problems like psychotic depression and schizophrenia give way to this sleep disorder. Thus, there are endless issues that cause this problem in individuals.
As earlier said that hallucination is a kind of sleep disorder, therefore it has a great relation with sleeping pattern. When a person bears severe deprivation of sleep, it leads him to this problem of hallucination. A normal person who does not have any sleep disorder takes his sleep on his time for around 8-10 hours a day. But, a person who starts following irregular sleeping pattern certainly leads to sleep deprivations and the gradual irregularity causes the problems like hallucinations or other sleep disorders. It has found that a person who does not sleep for 48 to 72 hours continually can get into hallucination.