What Are Parasomnias and How Do They Affect Your Sleep?

Learn what might be keeping you (and your partner) awake at night and what you can do about it

By Andrea Pisani Babich

Feb 4th, 2021

Expert Insights from Dr. Luis Javier Peña-Hernández, MD, FCCP, a lung health specialist at PCSI, the largest integrated pulmonary and chest specialty group in Palm Beach County.

They rob you and your bed mate of sleep, making you both irritable and cranky in the morning. They might startle you awake at night and leave you breathless with your heart racing and eyes wide open. They can even prompt you to say something you don’t really mean, eat something you don’t want, or do something completely out of character for you.

Nope, I’m not talking about your kids. I’m talking about parasomnias. And they, like your kids, come in a variety of forms.

What are parasomnias?

“Parasomnias are disruptive sleep disorders that can result in abnormal behavior while sleeping such as walking or talking,” explains Dr. Luis Javier Peña-Hernández.

In general, parasomnias are sleep disruptions that include unpleasant, disruptive behaviors and experiences that occur at any time during your sleep cycle. They can make getting a good night’s sleep challenging, increase stress, lead to injury and depression, and put a strain on your relationship with your significant other.

Occasional sleep disruptions are simply a part of life and can range from bad dreams to violent assaults on partners. Lots of people experience at least one parasomnia sometime in their lives. Many that occur in children resolve themselves as children grow older. But parasomnias that persist, get worse, or lead to debilitating sleep deprivation require attention.

There is usually a genetic predisposition for these phenomena, and they tend to be inherited from parents and run in families. Most are triggered by sleep deprivation from other underlying pre-existing sleep disorders (especially sleep apnea and restless legs syndrome/periodic limb movement disorder), as well as from stress, medications, alcohol abuse, etc, although they can also arise with no identifiable trigger (known as idiopathic). 

It is important to note that the occurrences are completely involuntary, and do not imply any underlying psychological disorder, as often used to be assumed.


At the very least, parasomnias are annoying to you or your partner because they disrupt your sleep. But some parasomnias can be downright dangerous because they involve behaviors that are not controlled by a mind that is awake and alert.

Like snoring, a parasomnia may not be remembered by the person experiencing it. If you suspect you are having sleep disruptions, you may need your partner to help you identify the issue. Here’s what you need to know about common parasomnias.

Different types of parasomnias and what to do about them

Non-REM parasomnias occur, as the name suggests, during non-REM sleep, usually during the earlier part of the night. The most common of these include:

REM parasomnias, which occur during the later REM stages of sleep, include:

We’ll go in-depth on these parasomnias below.


What is it?

A person experiencing confusional arousal will appear “out-of-it” when they wake up in the middle of the night. They may appear to be awake but acting abnormally. If someone is experiencing confusion arousal, they may also:

  • Speak slowly
  • Have a hard time understanding what is going on around them
  • Show poor memory
  • Respond bluntly to questions
  • Thrash around in bed or cry out

Morning sleep inertia is a variation of confusional arousal that occurs first thing in the morning and features the same confused behavior. People dealing with these disorders have no memory of their behavior, making it difficult to identify without a witness.

Rates of confusional arousal are higher among children and adults younger than 35. They appear in about 17% of children. Confusional arousals are usually harmless in children, although they can alarm parents watching their children behave so irregularly. Morning sleep inertia in adults can be disruptive or dangerous if it lasts into the school or workday or during the morning commute.

What can you do about it?

You should see a sleep specialist if you do not feel rested in the morning and suspect you are experiencing confusional arousals. Since confusional arousals may be caused by other disorders, treating those disorders is the first step in treating it. These potential causes include:

Your doctor will be able to determine if any of these issues is causing your confusional arousals. In addition to treating these conditions, you can:

  • Reduce your alcohol intake or eliminate it completely
  • Get a full night’s sleep consistently
  • Ask your doctor about antidepressants and sleep aids that have been shown to help with confusional arousals


What is it?

Also known as somnambulism, sleepwalking includes any activity a person does out of bed while still asleep. This can mean sitting up in bed, looking around in a confused manner with glassy eyes, and getting up to walk to another place in the house.

Other people may jump out of bed suddenly, talk or shout, or run away from their bedroom for no apparent reason. Often sleepwalking involves inappropriate behavior like urinating in a corner, moving furniture around, or climbing out a window.

People who sleepwalk can put themselves at risk by walking outside while they are asleep. It can be very hard to awaken a sleepwalker and sometimes they may become aggressive or violent when awakened.

Some of the causes of sleepwalking include:

  • Obstructive sleep apnea
  • Migraine headaches
  • Fevers (in children)
  • Sleep deprivation
  • Physical or emotional stress
  • Sleeping in a strange place
  • Alcohol use or abuse
  • Stroke
  • Hyperthyroidism

Sleepwalking is common among people with one or both parents who were sleepwalkers. Children who sleepwalk often experienced confusional arousals when they were younger.

What can you do about it?

Sleepwalking in children is fairly common and usually stops as children grow into their teen years. Since children can get injured if they stumble downstairs or leave the house, parents should monitor their children if they walk in their sleep during the evening. Parents might consider installing a baby gate to keep younger children in their rooms during the night. Keep the bedroom floor clear of obstructions that could trip or otherwise injure the sleepwalker.

Adults risk more serious injury if they sleepwalk, so they should see a sleep specialist to identify the cause of their sleepwalking. Often sleep apnea triggers a sleepwalker, so treating it can reduce sleepwalking episodes.


What is it?

Sleep terrors are one of the more alarming parasomnias that startle both the person experiencing it as well as bed partners and others in the household. A person experiencing a sleep terror, or night terror, will often scream or shout, kick, and thrash about the bed. They will look and feel terrified, with a contorted facial expression, racing heart, and heavy breathing. They may even bolt out of bed and run around the house.

Sleep terrors are more common among children than adults but still not a widespread problem. It affects an estimated 6.5% of children and only 2.2% of adults. Adults who have sleep terrors are likely to have a history of one of the following:

  • Bipolar disorder
  • Some depressive disorders
  • Anxiety disorders

Sleep terrors and sleepwalking share many of the same causes including:

  • Sleep deprivation
  • Hyperthyroidism
  • Migraine headaches
  • Head injury
  • Stroke
  • Premenstrual period
  • Physical or emotional stress
  • Obstructive sleep apnea
  • Travel
  • Alcohol use or abuse
  • Fevers (in children)

Sleep terrors can last as long as twenty minutes. During this time, it may be very hard to rouse or comfort the person experiencing a sleep terror. As a result, partners and household members may feel frightened and helpless during an episode.

What can you do about it?

Sleep terrors can be extremely upsetting to partners and family members. Children usually grow out of their tendency to have sleep terrors, and they typically do not need treatment. Adults are at a greater risk of injury, so those who experience frequent sleep terrors should see a sleep specialist.  Like many other parasomnias, sleep terrors are often caused by the sleep disruptions associated with obstructive sleep apnea. Treating sleep apnea may decrease episodes of sleep terror.


What is it?

Sleep talking, or somniloquy, is a common parasomnia that is harmless unless it is very disruptive to a sleep partner. The talk may be incomprehensible, very lucid, or anything in between. As many 50% of young children talk in their sleep and gradually grow out of the disorder as they become teenagers. Only 5% of adults talk in their sleep. Like sleepwalking, sleep talking appears to run in families.

What can you do about it?

Usually nothing. Sleep talking alone is rarely severe enough to require treatment. If it is associated with another more serious sleep disorder, a sleep specialist should be consulted for treatment of that disorder which may eliminate sleep talking.


What is it?

Episodes of SRED tend to occur when a person is only partially awake and consist of compulsive eating and drinking, usually in a frantic manner. Most people with SRED experience episodes almost every night that don’t seem to be triggered by hunger or thirst. Oddly, people with SRED will eat foods during the night that are often not what they prefer during their waking hours and are usually high in sugar and calories. They often respond with anger or resistance to attempts to stop them from eating. Rousing them is difficult when they are binging in their sleep.

Many more women than men experience sleep-related eating disorder, representing 65% – 80% of SRED patients. More than half of all SRED patients experience at least one other parasomnia, the most common being sleepwalking.

What can you do about it?

Sleep-related eating disorders should not be ignored. The effects of nighttime binging can lead to poor nutrition, weight gain, and depression as well as interfere with your sleep. People with SRED may also become ill from consuming toxic or inedible substances, or uncooked foods.

A sleep specialist can determine if another sleep disorder is triggering binging while asleep. Treating associated sleep disorders can improve the quality of your sleep and improve the symptoms of SRED. Medications and therapies used to reduce stress and anxiety can also reduce episodes of nighttime binging. 

Other sleep disorders associated with SRED include:


What is it?

People with this disorder act out the events of their dreams. It gets its name from the REM sleep stage in which it occurs. The dreaming person may:

  • Shout
  • Swear
  • Flail their arms
  • Grab something nearby
  • Punch the air, a pillow, or a partner
  • Kick the covers
  • Jump out of bed
  • Throwing a pillow

Early episodes tend to be milder than subsequent ones and so are often ignored. Left untreated, RBD episodes can become more violent that can lead to injury of the person experiencing RBD or their bed partner.

RBD is often confused with sleepwalking and night terrors, which also involve disruptive movements in and out of bed. RBD differs from these in that it is easy to wake a person during an RBD episode.

People with RBD have a higher risk of experiencing other sleep disorders such as:

  • Narcolepsy
  • Periodic limb movement disorder
  • Sleep apnea
What can you do about it?

Seek treatment of associated sleep disorders from a sleep specialist. The doctor can also prescribe medication to treat RBD and advise you about what medications should be avoided because they increase RBD symptoms.

Get the recommended amount of sleep for your age since sleep deprivation will exacerbate RBD. Take precautions to keep the bedroom safe for nighttime movements. Remove lamps and other objects from the nearby nightstand and keep the bedside floor clear of obstacles.

Because RBD can indicate the onset of Parkinson’s disease or multiple system atrophy, alert your doctor if you have tremors or other Parkinson’s symptoms.


What is it?

A person experiencing sleep hallucinations believes imaginary sights and sounds are real. They can also have hallucinations that involve touch, taste, and smell.

Unlike dreams or nightmares that are clearly not real, sleep hallucinations are mistaken for reality and, as such, can be very disturbing. They typically occur when a person is about to fall asleep or is just starting to wake up.

If sleep hallucinations occur during the day, they may be a sign of narcolepsy.

What can you do about it?

Sleep hallucinations appear to be very common, usually affecting teens and young adults. They tend to decrease in frequency as you get older. If they are troublesome in the meantime, consult with your doctor to determine if they are related to other issues.

Sleep hallucinations can be caused by other conditions such as:

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

Treatment for these conditions can decrease or eliminate sleep hallucinations. If they are a sign of narcolepsy, your doctor will prescribe narcolepsy medication. You can help yourself by:

  • Getting the recommended amount of sleep
  • Keeping a regular schedule
  • Limiting alcohol consumption
  • Avoiding certain drugs and medications that may contribute to hallucinations. Your doctor can give you specific advice.

Maybe if I ignore it, it will go away

Maybe. But when parasomnias occur frequently and/or increase in severity, it’s time to take action. Some parasomnias will go away on their own, but others can escalate or be a sign of a more serious condition.

“If you experience any abnormal behavior while sleeping, you may be experiencing a parasomnia such as confusional arousal, somniloquy, somnambulism, night terrors, bruxism, restless leg syndrome, or another sleep disorder,” says Dr. Peña-Hernández. “Speak with your primary care physician about your symptoms for a personalized recommendation for treatment.”

Parasomnias should not be ignored when:

  • They lead to sleep deprivation for anyone in the household
  • There is a risk of injury either to the person experiencing them or to others in the household
  • They escalate in severity or increase in frequency
  • They could be an indication of a medical or psychological problem
  • They are causing a strain on relationships at home

As disruptive and seemingly deliberate as some of these behaviors may appear, it is important for bed partners to understand that a person experiencing parasomnias has no intention of causing disruption or harm and usually will not even remember the episode in the next day. Partners can help by compassionately expressing their observations and feelings about the sleep disruptions and encouraging their partners to seek treatment from a doctor.

Many parasomnias are the result of lifestyle choices that can be adjusted for greater well-being. They tend to improve when a person:

  • Gets sufficient sleep regularly
  • Reduces stress and anxiety
  • Seeks alternatives to medications that may contribute to parasomnias
  • Consults with a doctor about medications that can help them sleep better

Parasomnias can be very frightening to experience as well as to witness. The fact that they happen in the dark when all else is quiet and peaceful magnifies the shock and alarm. And while the person behaving disruptively cannot control their behavior, they can take steps to help themselves, including consulting with a doctor.

Expert Bio

Dr. Luis Javier Peña-Hernández, MD, FCCP, is a lung health specialist at PCSI, the largest integrated pulmonary and chest specialty group in Palm Beach County. His areas of expertise include asthma and immunotherapy, COPD, lung cancer, and invasive diagnostic techniques in pulmonary medicine including endo-bronchial ultrasound and diagnostic bronchoscopy. He is also one of the few experts in cardiopulmonary exercise testing and exercise physiology in Palm Beach County.