What Exactly Is a Parasomnia?

Have you ever seen someone sleepwalking or been awakened by someone’s sleep talking? Each is a type of sleep issue known as parasomnias.

A couple in bed. The woman is sitting up with her arms crossed.
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Overnight awakenings are common. But if you or someone you know has mid-sleep conversations, sleepwalking tours of the house, regular nightmares, or even full meals while asleep, you may be experiencing a parasomnia. While these might not sound related, most strange or unusual behaviors around sleep can be categorized as parasomnias. Parasomnias are disorders that disrupt sleep.

These seemingly abnormal behaviors or dreams may make you appear awake even though you are not. Since parasomnias span a wide array of behaviors, they exist on a spectrum of danger. Some parasomnias are common, while some have bigger risks that may even pose as dangers to the sleeper or others in the house.

What are parasomnias?

Parasomnias are unpleasant behaviors that occur during rapid eye movement (REM) or Non-rapid eye movement (NREM) stages of sleep. These events can include movements, speech, or behaviors that would not normally happen during sleep and can interrupt sleep for the person experiencing the parasomnia, as well as others in the house. Parasomnias can also create concerns about emotional distress, daytime fatigue, and even safety.

Although sleepwalking and sleep talking are well-known parasomnias, other behaviors are also considered parasomnias. “Teeth grinding, bedwetting, and nightmares are common parasomnias,” says Annie Miller, a therapist and behavioral sleep specialist at DC Metro Sleep and Psychotherapy.

Often, parasomnias are suspected not by the person experiencing them but by a bed partner or housemate, as these symptoms can be witnessed by those around the person suffering from parasomnias. Often the person experiencing symptoms may not even be aware it is happening.


Different types of parasomnias

Parasomnias are organized into different types: NREM, REM, and other parasomnias. The parasomnia type is determined based on which stage of sleep the person is in when the symptoms happen.

NREM parasomnias

NREM sleep has three stages that progress toward deeper sleep. Roughly 75% of sleep is NREM. NREM parasomnias are repeating episodes of incomplete waking caused by abnormal behaviors or movements. Some of these episodes can present like seizures or sleepwalking.

REM parasomnias

REM sleep is the last stage of the sleep cycle. In this stage, dreaming occurs, and sleep is lighter and less restful. This causes a combination effect for parasomnias.

The parasomnias in this stage are often a mixture of dreams and behaviors, movements, or sleep paralysis. These parasomnias occur later in the night and can include a wider range of symptoms, such as nightmares and sleep eating.

Other parasomnias

Other parasomnias aren’t directly linked to NREM or REM phases. This makes it harder to put them into a category. Aside from bedwetting, these parasomnias are less common and include sleep hallucinations, exploding head syndrome (the sensation of hearing a loud sound during sleep stage transitions), and sleep talking.

Who suffers from parasomnias?

Adults and children can suffer from parasomnias. Men over age 50 are more likely to experience parasomnia symptoms, though the symptoms tend to link to another factor, such as an underlying neurological disease.

”Parasomnias can occur in anyone, but parasomnias like night terrors are more common in children. Some parasomnias, like REM Behavioral Disorder (RBD), are more common in adults,” Miller states.

The root causes of parasomnias      

There is no one sole cause of parasomnias. Causes may be related to other medical conditions or environmental factors like noise or poor sleep conditions. Sleep disruptions, medications, or inadequate sleep schedules can all lead to parasomnias.

“Stress and trauma are very important factors in parasomnias,” says Miller. “For instance, it has been shown that up to 80% of people suffering from PTSD experience nightmare disorder within a few months of the trauma.

Certain medications, as well as alcohol and drug abuse, can be risk factors for parasomnias. Genetics can play a role in the development of parasomnias as well. So, if a parent or other family member has, or had, a parasomnia, there is an increased risk of experiencing it.”

Risk factors for parasomnias can depend on the disorder. When sleepwalking is the symptom, there could be a hereditary link between parent and child. Sleepwalking may also be evident in people who suffer from restless leg syndrome, sleep apnea, or use certain medications for blood pressure, depression, and mental health disorders.

Night terrors most typically occur in children and are much less common in adults. When present in adults, night terrors are often related to depression, anxiety, or obsessive-compulsive factors.

The cause of sleep eating is less clear. Research shows it is a combination of sleep disorders often related to depression, anxiety, or obsessive-compulsive disorder and the eating disorder bulimia nervosa. Food and drink are taken in quickly, often without control. The person may not be aware of or later recall eating during sleep, though they appear fully awake to bystanders. This may be linked to an eating disorder, alcohol or substance use, or mental health issues.

RBD can be linked to medication, drug use or withdrawal, or neurological diseases like Parkinson’s, dementia, or stroke.

Sleep paralysis can be random and may happen only once or regularly. Hallucinations can occur with paralysis making it more frightening. A lack of sleep due to irregular sleep schedules can cause this pattern.

Bedwetting, or sleep enuresis, happens most often in children. This is more common in boys than girls and extends beyond age 6. Children don’t sense that their bladders are full, so do not wake up. Bedwetting may or may not be related to a separate medical condition — an evaluation is necessary to determine the cause.

Getting a diagnosis of parasomnia

The diagnosis of parasomnia is done through a medical evaluation with an in-depth medical history and, when possible, a witness to the events. A mental health screening is often included, as many parasomnias are linked to psychological causes.

Testing can include video polysomnography (PSG) with electroencephalogram (EEG) and electromyography (EMG) to determine if unusual brain or muscle activity takes place during sleep.

The goal of diagnosis is to determine the triggers or causes.

Non-medical treatments for parasomnia

After the parasomnia diagnosis is determined, treatment focuses on overcoming the cause of the parasomnia. One goal is initiating safe, effective sleep hygiene in a safe, sleep-conducive setting. Your doctor might first ask you to make the environment safe by:

  • Putting soft padding or additional pillows in your sleep space      
  • Removing sharp objects and/or padding corners around you     
  • Eliminating objects that could cause injury     
  • Gating stairwells and blocking areas where someone could fall
  • Trying out alternative sleep arrangements, if needed, by introducing or removing a sleep partner for safety     

Once the sleep space is secure, they might try non-medical approaches such as scheduled awakenings. “If there is a certain time of night that the parasomnia often occurs, you set an alarm or wake the person up prior to the time of the parasomnia,” Miller says. “This helps to disrupt the pattern. Relaxation strategies, mindfulness, and breathing also can be beneficial in relaxing the nervous system prior to bedtime.”

Other parasomnia treatments           

If scheduled awakenings and relaxation strategies don’t work, your doctor may then suggest trying specialized therapies. “Several strategies are available and very effective in treating parasomnias,” Miller explains. “CBT-i [cognitive behavioral therapy for insomnia] involves working on thoughts and behaviors around sleep. CBT-i strategies include setting a consistent sleep and wake time, as well as making sure to use the bed only for sleep and staying out of bed unless you are asleep. CBT-i is typically used for insomnia and trouble sleeping, but it can help with parasomnias by creating consistency and reducing fear and stress around sleep.

“For nightmare disorder, two types of therapy are clinically proven to be effective. Image Rehearsal Therapy (IRT) is a brief therapy that involves the nightmare sufferer to rewrite their nightmare to have an alternate ending. The other therapy, Exposure, Relaxation, and Rescripting Therapy (ERRT), also involves rewriting the nightmare but adds progressive muscle relaxation before going to bed.”

Medications are also available if alternative therapies are not effective. Melatonin is a natural sleep supplement that has been shown to help decrease some mild parasomnias. Healthcare providers can assist with other prescription medications for more frequent or intense parasomnias.

Contact your healthcare provider if you have concerns about whether you or someone in your home has parasomnias. Let your provider know if episodes are frequent, repeated, or impact daily functioning. Parasomnias can impact your safety and potentially cause injury, so taking precautions is important. Work with your provider to establish which parasomnia interrupts your sleep and determine the best ways to treat it. Your provider may need to investigate the cause of your parasomnia to choose the treatment options and how to improve your sleep routine.

Frequent questions about parasomnias

What disorder causes parasomnia? 

There is no one disorder that causes parasomnias. However, psychiatric and neurological disorders have been linked to an increased risk of parasomnias.

What is the difference between a sleep-related disorder and a parasomnia? 

Parasomnia sleep disorders cause abnormal activities during sleep, such as sleep terrors or sleepwalking. Dyssomnia sleep disorders cause trouble falling asleep or staying asleep.

How do you test for parasomnia? 

While you may first visit your doctor to help make an initial diagnosis, they may also refer you to a sleep specialist to further examine your sleep behavior. Diagnosis usually includes a review of your medical history, sleep history, or a sleep study.

What kind of doctor treats parasomnias? 

Parasomnia is typically treated by a sleep medicine specialist with extensive training in neurology. A physician who is board certified in sleep medicine and neurology, who demonstrates expertise in both fields by passing rigorous exams, is most qualified to treat these disorders and conditions.