If you have ever experienced extreme sleep deprivation, you may begin to question your sanity, especially if you start to see things that you know are not there. You may even wonder: Can sleep deprivation or insomnia cause hallucinations to occur?

Learn about the role of losing sleep and the subsequent development of visual hallucinations. Find out when it occurs, how long it takes for hallucinations to develop with sleep loss, and how to reverse the effects.

What Are Hallucinations?

A hallucination is the perception of something that is not really present in the environment, as opposed to an illusion, which is the misinterpretation of something that is present.﻿﻿ For example, seeing a cat where there is nothing is a hallucination, but mistaking your coat rack for a person is an illusion.

Verywell / Cindy Chung

Causes of Sleep Deprivation

There are many reasons that people get inadequate sleep and become sleep deprived. Some causes will be obvious while others may require evaluation and testing in a sleep clinic. Consider these possibilities:

Not meeting minimum sleep needs (often seven to eight hours in adults)

Work demands

Home life (caregiving responsibilities or chores)

Shift work sleep disorder

Insomnia

Delayed sleep phase syndrome (night owls)

Obstructive sleep apnea

Narcolepsy ﻿ ﻿

Do any of these options seem familiar? Depending on the degree of sleep deprivation—both how little we sleep and for how long we are sleep deprived—there can begin to be important consequences to our health and well-being.

Total vs. Incremental Sleep Loss

Total sleep deprivation, in which no sleep is obtained for several nights in a row, certainly can be a trigger. Chronically obtaining too few hours of rest may likewise have a cumulative role.

The degree of sleep deprivation required to start to experience side effects likely varies for each person depending on their individual sleep needs and genetic predisposition toward hallucinations.

If someone needs 10 hours of sleep to feel rested, but only gets eight hours, they will gradually become sleep deprived. This occurs even though they may seem to be getting enough sleep based on the population average.﻿﻿

Effects in Children and Teenagers

Sleep deprivation can affect both children and adults. Children need more sleep, and not getting it may lead to behavioral and growth problems. They can even hallucinate.

Adolescents who are night owls with delayed sleep phase syndrome may have difficulty meeting their sleep needs due to a delay in the onset of sleep and required wake times for school.﻿﻿

Falling asleep late, and waking too early, may lead to a cumulative sleep loss. This may be compensated for with excessive sleeping on weekends or even napping—or lead to problems.

Hallucination Types

Beginning to hallucinate is among the more common symptoms of sleep deprivation. Depending on the length of sleep deprivation, approximately 80% of normal people in the population will eventually have hallucinations.﻿﻿ Most of these are visual hallucinations. These visions may be simple or complex.

In contrast, people with schizophrenia often have auditory hallucinations, hearing sounds (often voices) that are not there. These voices may even tell the affected person what to do, a phenomenon called command hallucinations.

Disorientation and Paranoia

Sleep deprivation can actually cause other symptoms that mimic mental illness, such as disorientation and paranoid thoughts. In fact, one study found that 2% of 350 people who were sleep-deprived for 112 hours experienced temporary conditions that were similar to acute paranoid schizophrenia.﻿﻿

The affected person may be confused about details related to time or location. The paranoia may lead to feelings of persecution.

Recovery Sleep Ends Hallucinations

Fortunately, these symptoms resolve when adequate sleep is obtained. So if you see something that isn’t there during a period of sleep deprivation, don't fret: it might simply be time to get some rest.

There is considerable evidence that just one night of adequate recovery sleep can be enough to reverse the various effects of sleep deprivation.

A Word From Verywell

If your symptoms persist despite getting adequate rest, consider speaking with your doctor. In rare cases, further evaluation may prove necessary to get to the bottom of the problem.