Home » Sleep Disorders » Sleep Hallucinations
December 2020 |  Reviewed by:  Imran Shaikh, MD and Reeba Mathew, MD

What are sleep hallucinations?

Sleep-related hallucinations is a sleep disorder and is categorized as a parasomnia. A parasomnia involves undesired events that come along with sleep.

Sleep hallucinations are imagined events that seem very real. They are mainly visual. They may also involve your senses of sound, touch, taste, and smell. They may even involve a sense of motion.

It is easy to confuse them with a state of dreaming. You may not be sure if you are awake or asleep. They may be like nightmares; however, when you wake up from a nightmare, you are aware that it occurred while you were asleep. Nightmares are clearly recognized as a dream and are not thought to be real.

You may also have complex visual hallucinations in the form of stationary images of people or animals. These tend to occur just after you are suddenly awakened. You do not recall being in the middle of a dream when you wake up. You know that you are awake. At first, you are often afraid and think that the images are real. You may jump out of the bed in terror. This can cause you to injure yourself.

These images may be distorted in shape or size. They may remain present for many minutes. They tend to go away if a light is turned on. These episodes are much rarer. At times they may be caused by a migraine headache. In this case, head pain quickly follows the visual images.

Sleep hallucinations generally occur at one of the two following times:

  • As you are about to fall asleep
  • As you are just waking up

Sleep hallucinations can be a sign of narcolepsy, especially if the events occur during the daytime.

Sleep hallucinations and sleep paralysis may occur at the same time. You may also have separate episodes of sleep talking or sleepwalking.

What are symptoms of sleep hallucinations?

You may have sleep hallucinations if you:

  • Imagine events that seem very real just before falling asleep or just after waking up, and
  • These imagined events are mainly visual

It is also important to know if there is something else that is causing these episodes. They may be a result of one of the following:

  • Another sleep disorder such as narcolepsy
  • A medical condition
  • Medication use
  • A mental health disorder
  • Substance abuse

What are risk factors for sleep hallucinations?

Sleep-related hallucinations seem to be very common. They have been reported by as many as one-third of all people. They are more common in teens and young adults. In many people, the episodes tend to decrease with age. They also occur slightly more often in women than in men. They are very common in people who have narcolepsy. Factors that can cause them include the following:

  • Current drug use
  • Past alcohol use
  • Anxiety
  • Mood disorders
  • Insomnia

They can also be due to an epileptic seizure. In this case, they tend to be brief, visual fragments.

How to diagnose sleep hallucinations

You should see your medical provider if hallucinations cause you great anxiety or often disrupt your sleep. If you have them along with severe daytime sleepiness, then you may have narcolepsy. Narcolepsy should be diagnosed and treated by a sleep doctor.

The doctor will need to know when the hallucinations began. She will want to know how often they occur and how long they last. The doctor will need to know your complete medical, psychiatric, and sleep history. The doctor will want to know if you are unusually sleepy or have any other sleep problems. Be sure to inform her of any drug and medication use, both past or present.

Tell your doctor if you have ever had any other sleep disorder. Find out if you have any family members with sleep problems. It will also be helpful if you fill out a sleep diary for two weeks. The sleep diary will help the doctor see your sleeping patterns. This data gives the doctor clues about what is causing your problem and how to correct it.

Your doctor may have you do a sleep study if your problem is severely disturbing your sleep. This study is called polysomnography. It charts your brain waves, heartbeat, and breathing as you sleep. It also records how your arms and legs move. This study will help reveal if the hallucinations are related to any other sleep disorder.

If you tend to be very sleepy during the day, then your doctor may also have you do a daytime nap study. This is called a Multiple Sleep Latency Test (MSLT). The MSLT will measure how fast you fall asleep during the day. It will also show what kind of sleep you have when you take a nap. It will help to show if your hallucinations are a sign of narcolepsy.

How to treat sleep hallucinations?

Sleep-related hallucinations may or may not need treatment. They tend to decrease with time. They may also decrease as you do the following:

  • Get enough sleep
  • Keep a regular sleep schedule
  • Avoid alcohol and certain drugs and medications

If they are causing sleep disruption or anxiety, then the doctor may prescribe medications to help you. The doctor may also change any current medications you may be taking for depression or anxiety.

If the hallucinations are a sign of another sleep disorder, such as narcolepsy, then treatment of the underlying sleep disorder should be followed.