What is the Difference Between Nightmares and Night Terrors?

Patient Presentation
A 30-month-old male came to clinic for his health supervision visit. His father had no general concerns except for the past 4 months the child had been wakening at night. “It’s really scary. He just starts to scream. We go into his room and he’s sitting there screaming and crying. Nothing we do makes any difference. We hold him and he doesn’t seem to notice, and he’s shaking and sweaty. Then he just seems to go back to sleep. He doesn’t remember any of it, but we sure do,” the father recounted. The episodes were similar to each other and occurred in the earlier part of the night. They seemed to occur more after a busy day. He had no problems during naps and had not had any problems sleeping before this time. He had no snoring or breathing problems when he slept. He was meeting his developmental milestones. The past medical history was positive for recurrent otitis media and viral upper respiratory tract infections. The family history was negative for sleep problems. The pertinent physical exam showed an interactive boy with normal vital signs and growth parameters in the 75%. His examination was normal.

The diagnosis of a healthy 30 month old with sleep terrors was made. The medical student asked the pediatrician about the differences between nightmares and night terrors. “Well first there is age. Nightmares and sleep terrors occur when the kids are younger so those are more common in his age group. Then I think about “Who is scared?” the parent or the child. If the parent is scared its usually sleep terrors but if the child is scared it is nightmares. There are other parasomnias too that should be considered but those are the most common. Let’s talk some more after clinic about them,” she offered.

Sleep disorders are common in all ages particularly with sleep deprivation in our increasingly busy world. Sleep problems are more common in patients with attention deficit hyperactivity disorder, epilepsy, headache and visual impairments. Sleep problems can cause cognitive and behavioral impairments including emotional regulation problems, increased seizures or headaches, and impaired attention and have been known to prolong recovery from various acquired brain injuries.

Parasomnias are “undesirable events that accompany sleep and typically occur during sleep-wake transitions.”

The term sleep terror is preferred to night terror as these episodes can occur during any sleep period, daytime or nighttime. One of the key elements is that the terrorized person is not the child but the family member who is often quite alarmed and distressed by the appearance and behavior of the child. The episodes have an abrupt awakening with screaming/crying with strong autonomic discharge including tachycardia, tachypnea and sweating where the child is not aware of what is going on. The episodes are generally brief and the child is amnestic of the event later on.

A 2015 study found a sleep terror prevalence rate of 34.4 % of 18 month olds that slowly decreased to 5% at age 13. There was a similar inverse trend for sleepwalking with a prevalence rate of 12.8% at age 13 that decreased to 3.6% at age 18 months. The authors note that there is a strong familial association with these 2 parasomnias and they may be manifestations of the same underlying pathophysiological entity.

Learning Point
Characteristics of common childhood parasomnias include:

  • Sleep Terrors
    • “Terrorizes the Parent”
    • Age: 2-4 years, decrease overtime and generally stop by adolescence
    • Time of night: Anytime but often first 1/2 of sleep, may occur during any sleep period including daytime naps
    • Sleep stage: Non-REM
    • Episode elements:
      • Abrupt awakening with crying/screaming
      • Strong autonomic signs with tachycardia, tachypnea and/or sweating
      • Not aware of what is happening, does not appear awake, cannot generally be comforted
      • Amnestic for event during and later
      • Short, lasts few minutes and child goes back to sleep
      • Often scares the family but child is unaware
      • Overall generally benign
    • Other important features: Appears to be associated with somnambulism later in life, can be associated with psychopathology when occurring in adolescents and adults
    • DDX: nightmares, partial complex seizures (often occurs with stereotypical behaviors/posturing that can occur during wakefulness)
      Precipitating events: sleep deprivation, acute illnesses, and partial arousals such as bladder distention or obstructive sleep apnea

    • Tx: Parental reassurance, good sleep hygiene, treatment of underlying illness, safety measures to prevent from self-injury
  • Nightmares
    • “Scares the Child”
    • Age: School age
    • Time of night: Last 1/2 of sleep
    • Sleep stage: REM sleep
    • Episode elements:
      • Abrupt or not abrupt onset
      • Mild tachycardia
      • Is aware and awake, has negative emotional response to distressing dream
      • Able to be comforted
      • Has a longer period after awakening before going back to sleep
      • Is usually able to recount details to the distressing dream
      • Scares the child, usually does not scare the family as much
      • Overall generally benign
    • Other important features:
    • DDX: Sleep terrors, if frequent/severe may be underlying psychological or medical problem
    • Precipitating events: normal behavior, poor sleep hygiene, and stressful/traumatic events
    • Tx: Reassurance of parent and child, sleep hygiene
  • Confusional arousals
    • “Sleep Drunkenness”
    • Age: Preschool/school age
    • Time of night: first 1/2 of night
    • Episode elements:
      • Slowed responsiveness and slurred speech
      • Inappropriate behavior
      • Agitation, crying or moaning
      • Confusion after awakening
      • Amnestic for events afterward
      • DDX: Sleep terrors, nightmares, somnambulism
      • Precipitating events: sleep deprivation, acute illnesses
      • Tx: Parental reassurance, good sleep hygiene, safety measure to prevent from self-injury
  • Rapid Eye Movement Sleep Behavior Disorder (RBD)
    • “Acts Out the Dream”
    • Age: Adolescence to adulthood
    • Time of night: REM sleep
    • Sleep stage: Last 1/2 of sleep
    • Episode elements:
      • Does not have normal atonia that occurs during dreaming therefore patient can move
      • Dream reenactment behavior with talking, shouting, gesturing, moving
      • Generally active movement or vocalization not just quiet walking/whispering
      • Patient is interacting in the dream and not aware of actual physical surroundings
      • Vivid dream recall that is often frightening
      • Overall patients at risk for serious injury
    • Other important features: can be presentation of narcolepsy, can be associated with other neurological disease
    • DDX: Sleep walking, sleep terror, confusional arousal
    • Tx: Melatonin, benzodiazepines
  • Somnambulism
    • “Sleep Walking”
    • A review can be found here
    • Age: school age to adulthood
    • Time of night: first 1/2 of night
    • Sleep stage: first 1/2 of night
    • Episode elements:
      • Walking during sleep
      • More quiet movement and “interacts” with the actual world – navigates doors, stairs etc. but can have unusual or dangerous behaviors because not aware
      • Difficult to awaken
      • Rapid return to sleep
    • DDX: confusional arousals, nightmares
    • Precipitating events: sleep deprivation, acute illnesses
    • Tx: Parental reassurance, good sleep hygiene, safety measure to prevent from self-injury

Questions for Further Discussion
1. What is restless legs syndrome?
2. What is benign insomnia of childhood?
3. How common is obstructive sleep apnea in children?

Related Cases

To Learn More
To view pediatric review articles on this topic from the past year check PubMed.

Evidence-based medicine information on this topic can be found at SearchingPediatrics.com, and the Cochrane Database of Systematic Reviews.
Information prescriptions for patients can be found at MedlinePlus for this topic: Sleep Disorders

To view current news articles on this topic check Google News.

To view images related to this topic check Google Images.

To view videos related to this topic check YouTube Videos.

Haupt M, Sheldon SH, Loghmanee D. Just a scary dream? A brief review of sleep terrors, nightmares, and rapid eye movement sleep behavior disorder. Pediatr Ann. 2013 Oct;42(10):211-6.

Carter KA, Hathaway NE, Lettieri CF. Common sleep disorders in children. Am Fam Physician. 2014 Mar 1;89(5):368-77.

Petit D, Pennestri MH, Paquet J, Desautels A, Zadra A, Vitaro F, Tremblay RE, Boivin M, Montplaisir J. Childhood Sleepwalking and Sleep Terrors: A Longitudinal Study of Prevalence and Familial Aggregation. JAMA Pediatr. 2015 Jul;169(7):653-8.

Maski K, Owens JA. Insomnia, parasomnias, and narcolepsy in children: clinical features, diagnosis, and management.
Lancet Neurol. 2016 Oct;15(11):1170-81.

Donna M. D’Alessandro, MD
Professor of Pediatrics, University of Iowa