Night Terrors vs. Nightmares: Key Differences, Causes, and When to Seek Help

Waking to the sound of someone screaming, breathing heavily, or moving in panic can be deeply frightening. Yet not every alarming nighttime episode means the same thing.

Night terrors and nightmares are both parasomnias—unusual experiences or behaviors that occur during sleep. Although they may look similar from the outside, they develop during different stages of sleep and affect awareness and memory in very different ways.

Understanding that difference can replace fear with clarity and help families recognize when simple sleep changes may be enough—and when professional care is needed.

What Happens During a Night Terror?

A night terror, also called a sleep terror, is a partial awakening from deep non-rapid eye movement sleep, or NREM sleep. It usually happens during the first third or first half of the night.

A person experiencing a night terror may suddenly:

• Sit up or jump out of bed
• Scream, cry, or speak without making sense
• Breathe rapidly or have a racing heartbeat
• Sweat or appear flushed
• Wave their arms, push people away, or try to escape
• Look awake while remaining confused and difficult to comfort

During the episode, the person is not fully conscious. They may not recognize a parent, partner, or family member and may not respond normally to questions. Trying to wake them completely can increase confusion or agitation.

Most people settle back to sleep after several minutes, although some episodes last longer. By morning, they usually remember little or nothing about what happened.

Sleep terrors are especially common in children and often decrease as the nervous system matures. They are less common in adults, and new or frequent episodes in adulthood deserve closer evaluation.

What Makes a Nightmare Different?

A nightmare is a vivid, frightening dream that causes the sleeper to wake up. Nightmares are more closely associated with rapid eye movement sleep, or REM sleep, and therefore tend to occur later in the night, when REM periods become longer.

After a nightmare, the person usually becomes fully alert and can often describe the dream in detail. They know where they are, recognize the people around them, and may seek reassurance.

This is the central difference: A person usually remembers a nightmare but does not remember a night terror.

Nightmares may involve fear, danger, helplessness, loss, shame, or other intense emotions. An occasional nightmare is a normal human experience. It becomes a clinical concern when frightening dreams happen repeatedly, disturb sleep, create a strong fear of going to bed, or interfere with daytime functioning.

Night Terrors and Nightmares at a Glance

Night terrors:

• Usually occur during deep NREM sleep
• Are more common earlier in the night
• Involve incomplete awakening and confusion
• Make the person difficult to comfort
• Usually leave little or no memory
• Are especially common in childhood

Nightmares:

• Usually occur during REM sleep
• Are more common later in the night
• Cause a fuller awakening
• Allow the person to respond normally
• Are often remembered clearly
• Can occur at any age

Both conditions belong to the broader group of parasomnias, but they should not automatically be treated in the same way.

Why Do These Episodes Happen?

There is rarely one simple explanation.

Sleep terrors may become more likely when deep sleep is disrupted. Possible contributing factors include:

• Sleep deprivation
• An irregular sleep schedule
• Emotional stress
• Fever or illness
• Travel or changes in routine
• Alcohol use
• Certain medications
• Other sleep disorders, including sleep-disordered breathing

Family history may also play a role. Some children who experience sleep terrors have relatives with a history of sleepwalking or other NREM parasomnias.

Nightmares are often connected with stress, anxiety, trauma, major life changes, disrupted sleep, alcohol, or certain medications. They may also occur alongside post-traumatic stress disorder (PTSD), depression, anxiety disorders, insomnia, or other health conditions.

Still, having a nightmare does not automatically mean that a person has a psychiatric disorder. The frequency, intensity, and effect on daily life matter far more than a single episode.

What Should You Do During a Night Terror?

The most important goal is safety.

Stay calm and avoid shouting, shaking, or forcefully waking the person. Speak quietly and guide them away from stairs, windows, sharp furniture, or other hazards. Restrain them only when necessary to prevent immediate injury.

For a child with night terrors, parents can make the bedroom safer by securing windows, clearing the floor, blocking access to stairs, and maintaining a regular bedtime routine.

When episodes occur at almost the same time each night, a clinician may suggest scheduled awakenings. This means gently waking the child shortly before the expected episode for several nights or weeks. Research suggests that this approach may help some children, although the evidence for treatments of NREM parasomnias remains limited.

What Can Help With Recurrent Nightmares?

A stable sleep schedule is a useful starting point. It may also help to reduce alcohol, avoid heavy meals close to bedtime, and create a calmer transition into sleep.

Any medication changes should be discussed with a healthcare professional rather than made independently.

For persistent nightmares, especially those connected with trauma, imagery rehearsal therapy (IRT) may be helpful. In this treatment, the person rewrites the nightmare while awake, gives it a less threatening ending, and mentally rehearses the new version.

The American Academy of Sleep Medicine recommends imagery rehearsal therapy for nightmare disorder and trauma-related nightmares. Other forms of cognitive behavioral treatment may also be considered. Medication is sometimes used for specific conditions, but it should be selected only after an individual medical assessment.

When Is Professional Help Needed?

Occasional episodes usually do not require medical treatment. Consider contacting a primary care doctor, pediatrician, or sleep medicine specialist when:

• Episodes happen frequently or become more intense
• Someone is injured or at risk of injury
• Sleep disruption causes daytime exhaustion
• A child develops a strong fear of going to bed
• Nightmares are connected with trauma or severe anxiety
• Episodes begin unexpectedly in adulthood
• There are unusual movements, stiffening, breathing pauses, or other possible signs of seizures or sleep-disordered breathing
• The behavior is affecting relationships, school, work, or quality of life

A sleep diary can help. Record bedtime, wake time, stress, alcohol or caffeine use, medications, illness, and the approximate time of each episode. This information may reveal patterns and help a clinician decide whether further testing is necessary.

Treatment Should Fit the Person

Most childhood night terrors improve with time, adequate sleep, reassurance, and a safer sleep environment. Medication is rarely the first choice for uncomplicated childhood episodes.

Persistent nightmares require a different approach. Treatment may focus on trauma, anxiety, insomnia, medication effects, or another underlying condition. Effective care is not simply about suppressing a frightening symptom—it is about understanding what keeps disturbing the person’s sleep.

A terrifying night can leave an entire household unsettled. But knowledge changes the emotional weight of the experience. Once night terrors and nightmares are correctly recognized, they become less mysterious—and far more manageable.

References

• Leung AKC, Leung AAM, Wong AHC, Hon KL. Sleep Terrors: An Updated Review. Current Pediatric Reviews. 2020;16(3):176–182.
  Reviews the symptoms, typical course, contributing factors, diagnosis, and management of sleep terrors, especially in children.
• Irfan M. Sleep Terrors. Sleep Medicine Clinics. 2024;19(1):63–70.
  Provides a current clinical overview of sleep terrors as disorders of arousal and discusses evaluation, safety measures, triggers, and behavioral management.
• Sateia MJ. International Classification of Sleep Disorders—Third Edition: Highlights and Modifications. Chest. 2014;146(5):1387–1394.
  Explains the major categories of sleep disorders and the clinical classification of parasomnias used in sleep medicine.
• Morgenthaler TI, Auerbach S, Casey KR, et al. Position Paper for the Treatment of Nightmare Disorder in Adults. Journal of Clinical Sleep Medicine. 2018;14(6):1041–1055.
  Presents the American Academy of Sleep Medicine’s recommendations for treating nightmare disorder, including imagery rehearsal therapy and options for trauma-related nightmares.