All about nightmares and night terrors
What's the difference between a nightmare and a night terror?
A nightmare is a highly distressing dream which often wakes the dreamer with disturbing emotions such as anger, anxiety, fear, guilt, sadness or depression. Nightmares are common but themes do vary significantly from person to person and are influenced by a number of environmental, emotional and physiological factors.
Nightmares occur during REM (Rapid Eye Movement) sleep, which is typically considered the lightest sleep stage. Nightmares generally occur just before waking – periods of REM sleep extend for longer periods of time in the early morning. 
In addition, someone who is having a nightmare can generally be woken and comforted and the nightmares – and the emotions they evoked – are often recallable, at least in part. 
In contrast, a night terror occurs during the non-REM phase of sleep. And, while nightmares will affect sleepers of all ages, night terrors are generally only experienced by children, aged from around three to 11 years. It’s estimated one to six percent of children experience night terrors. 
Non-REM sleep is divided into four stages. Night terrors occur during the transition from stage three non-REM sleep to stage four non-REM sleep, beginning approximately 90 minutes after the child has fallen asleep. Typically, the child sits up in bed and screams, appearing awake but confused, frightened and disoriented but unresponsive. They will not seem aware of a parent’s presence, usually don’t talk and may thrash around in bed. They don’t respond to comforting, can’t be woken and won’t be able to recall the episode the following morning.
While the episode itself only lasts for a short amount of time, it may take up to half an hour for the child to calm down and sleep again.
What causes nightmares?
Just about everyone has nightmares at one time or another. However, it’s children who experience them most frequently. A 2000 research paper published in the journal Sleep on the impact of disturbing dreams in children and adolescence argues that childhood nightmares don’t necessarily signal unusual problems. Rather, the research has discovered, nightmares are a part of normal childhood development.
Possible causes of nightmares for children
Children may experience nightmares because of:
- the ordinary stresses and strains of growing up
- a traumatic event, such as an accident or surgery
- a fever
- an active imagination.
In addition, if a child has recurrent nightmares, or the content of a dream is particularly disturbing, the child might have experienced – or be experiencing – some type of trauma. Trauma can result in a child experiencing nightmares for several weeks or months after the fact.
How to prevent and treat nightmares for children
It isn’t possible to stop your child from ever having another nightmare, but you may be able to reduce the frequency of bad dreams:
- Make sure your child doesn’t watch frightening shows on television or read scary books.
- Consider your child’s daily routine. Is anything troubling them? Stressful events that could trigger a spate of nightmares include a new sibling, moving house or starting school.
- Talk about dreams together and explain that everyone has dreams and occasional nightmares.
- If your child is troubled by a recurring nightmare, help them to explore its meaning through drawing, writing or play acting. Thinking about the nightmare creatively – especially when the child comes up with a happier ending or ‘makes friends’ with the nightmare character – can help to defuse the power of the dream.
It’s important to note that nightmares that repeat traumatic events reflect a normal psychic healing process. This will diminish in frequency and intensity with time and as recovery progresses. But, if after several weeks no change is noted, professional consultation should be sought.
What causes night terrors?
Night terrors are far less common than nightmares and predominantly only affect children. But like nightmares, there are usually no long-term psychological effects.
A prominent 2000 study, published in The Diagnostic and Statistical Manual of Mental Disorders, 4th Edition, reveal that there’s some evidence that a predisposition to night terrors is congenital. In this study, individuals frequently reported that past family members had episodes of sleep terrors. In some studies, a tenfold increase in the prevalence of the disorder in first-degree biological relatives had been observed. However, more research into the exact link to inheritance is required.
In addition, a 2001 study published in Sleep and Hypnosis Journal determined that the occurrence of stressors in a child’s life (eg. hospitalisation, problems at school, parental divorce and amount of TV consumption) were also associated with the prevalence of night terrors.
Other possible causes of night terrors deduced include:
- Sleep deprivation
- Sleeping in unfamiliar surroundings
- Lights or noise
How to prevent and treat night terrors for children
Night terrors may seem scary to parents but they don’t harm the child, who won’t remember them in the morning. During a night terror episode, it might be impossible to console the child as they aren’t consciously aware of their surroundings. Instead, avoid waking the child during a night terror as they’ll only be confused and disorientated if woken, and might take longer to settle. If you think the child might hurt themselves during the episode, stay close to guide them away from hitting or bumping the sides of the cot, bed or other obstacles. It’s also best to wait for the child to stop thrashing around and then guide them back to bed to settle.
Creating a bedtime schedule can increase the chances of a restful night’s sleep and avoid overtiredness, which is a possible trigger for night terrors.
If the night terror happens at the same time every night, it can help to completely wake the child 15 minutes before this time, letting them drift off to sleep again. This can be very effective – usually after a few nights of this you can stop the partial waking and see if the night terrors have stopped.
If you’re still concerned, or the night terrors seem prolonged or violent, it is important to seek professional advice. If night terrors are occurring along with other sleeping difficulties – or your child also has breathing problems, such as snoring – talk with your doctor about an ear, nose and throat assessment.
This article was written by Kylie Matthews for Kidspot – New Zealand's leading parenting resource for toddlers and preschoolers.