Not enough sleep and seeing things that aren’t there?

Staying awake for two days or more can result in you experiencing hallucinations as your brain has not had time to properly rest and reset. — AFP

I recently met a young man who had severe insomnia. He could only get two to three hours of sleep a night. It affected him so badly that he could not work properly and even had to quit his job. He says he also has been having hallucinations, seeing shadows of people in the periphery of his vision. He is not sure if they are ghosts! Can severe sleep deprivation cause hallucinations?

Yes, it can.

People who are too tired can start seeing shadows that move or hear things where no source has made any sound.

People who are extremely exhausted can get hallucinations.

Hallucinations become more likely when you have been awake for 48 to 72 hours straight.

What exactly are these hallucinations?

Hallucinations are false ­perceptions.

The important word here is “false”.

They can be:

> Auditory (sound)

These are the most common.

You may hear sounds that are not real, e.g. people calling your name, people speaking, music playing, a door shutting, or even footsteps.

> Visual (sight)

These are less common than sound hallucinations, but can still happen.

You may glimpse things that are not real, like shadows, people, animals, lights and objects.

> Tactile (touch)

You may “feel” bugs crawling on your skin or someone touching you.

You may even feel your ­internal organs moving around.

> Olfactory (smell)

You may smell something no one else around you can.

> Gustatory (taste)

You may taste something strange and usually unpleasant, like a metallic taste.

> Presence

You may feel that someone is in the room with you or standing behind you.

> Proprioceptive

You may feel as if you are floating or flying when you are not.

There are also some hallucinations that are specifically related to sleep.

Hypnopompic hallucinations happen just as you are waking up from sleep.

Meanwhile, hypnagogic hallucinations happen just as you are about to fall asleep.

These types of hallucinations are mostly visual and have a short duration. You need not worry about them.

Why do we get hallucinations if we don’t get enough sleep?

Basically, you need sleep in order to survive.

Your brain goes through several sleep cycles a night, comprising non-REM (rapid eye movement) sleep and REM sleep.

Non-REM sleep is needed for restoration of your brain ­processes and mental faculties.

REM sleep (during which dreams occur) are for emotional processing and memory consolidation, which is why you often dream of some unresolved event or trauma.

You go through these sleep stages four to six times a night.

When you don’t get enough sleep, your brain has to skip or shorten your deep non-REM sleep.

It may enter REM sleep too quickly.

Your sleep becomes short, unstable and erratic.

Because your body didn’t have enough time to rejuvenate the brain, and consolidate your emotions and memories, this could lead to hallucinations.

So, if your sleep deprivation is very severe, your brain can malfunction and cause you to have hallucinations in these ways:

> REM intrusion

Your brain could slip into REM-like activity while you are still awake.

This means that your dream images actually leak into your waking state.

That is why you can “see” or “hear” shadows, sounds or ­people who are not really there.

> Microsleep

If you don’t sleep for one day, your brain can enter into microsleep, which shuts down your brain for a few seconds.

You may stare blankly into space and experience dream-like images.

You are “awake”, but your brain isn’t fully functioning.

> Misinterpret sensory data

When you are very tired, your brain’s frontal cortex – which is supposed to help you with logic and judgment – is less active.

But the parts of your brain that involve emotions become more active instead.

So you may end up misinterpreting shadows as people and hearing background noises as voices as your brain is incorrectly filling up the gaps.

Are sleep-deprived hallucinations very vivid? Like entire scenes and conversations and such?

They tend to be very mild.

The hallucinations tend to be “simple” ones like seeing shadows out of the periphery of your eyes, seeing patterns or walls “move”, hearing your phone ping when it didn’t, seeing an insect moving when there isn’t one, or feeling that someone is in the room with you when you are alone.

Because you are sleep-deprived, you tend to be scared as well – some people think they are seeing ghosts!

The good news is that these hallucinations can stop once you go to sleep and your brain gets a chance for proper rest.

What if my hallucinations are something more sinister?

You mean actual ghosts?

Not likely!

What is more likely is that you may have a psychiatric disorder if your hallucinations:

• Are still there even if you have had a few nights of good sleep
• Are vivid, detailed and very distressing, like voices talking about you or to you, or seeing people in full detail
• If you have mood swings
• If you are extremely depressed.

These type of hallucinations can occur in psychiatric conditions like bipolar disorder, major depression and schizophrenia.

They may also occur if you abuse drugs or are undergoing withdrawal from illegal drugs.

Dr YLM graduated as a medical doctor, and has been writing for many years on various subjects such as medicine, health, ­computers and entertainment. For ­further information, email [e-mail]. The information provided is for educational and communication purposes only, and it should not be construed as personal medical advice. Neither The Star nor the author gives any warranty on accuracy, completeness, functionality, usefulness or other assurances as to such information. The Star and the author disclaim all responsibility for any losses, damage to property or personal injury suffered directly or indirectly from reliance on such information.