This is a fact sheet about Nightmares. Nightmares are distressing and vividly frightening dreams that occur during REM (rapid eye movement) sleep.

Young girl with arms on her head facing away. Photo by Meruyert Gonullu.
calendar icon
January 12, 2024
time, clock icon
min read


Things you should know:

  • Nightmares are most common in children, but adults can get them too.
  • They can be set off by many things such as stress, trauma, or mental/physical illness.
  • For some people, there is no known cause.
  • You might think they are harmless, but they can happen so often that you don't get enough sleep at night.
  • There are ways to treat them (e.g., drugs), or you can learn how to control your dreams.
  • If they are due to an event in your life, you can get counselling to deal with this.

What are nightmares?

Nightmares are vivid scary dreams. They tend to wake you up. They may often also stop you going back to sleep due to fear. Many children have them, but they tend to stop between ages 9 to 11. If they keep going past this age and are not due to stress or trauma, then the person might keep having them for the rest of their life. These are known as idiopathic nightmares (start in childhood and not from trauma). They can also start at any age after periods of stress, trauma, and the start of a mental or physical illness. A child will often dream of frightening imaginary creatures, e.g., monsters or ghosts. An adult may dream images of events which either threatening or harmful in some way. These can be real or imaginary. Nightmares with a link to trauma tend to have vivid images from the event e.g., assault, bushfire, accident, war etc. No matter what the cause, they tend to have the same effects:

  • Waking up suddenly due to the nightmare. This often occurs about 90 minutes after going to sleep. It can occur over and over for the rest of the night. The time between them is often around 90 minutes.
  • Rapid heart rate as well as fear. The person may sweat.
  • Seeing vivid images or scenes where something bad was done to the person e.g., humiliated, threatened or harmed.

If a child or adult becomes very distressed in their sleep but has no memory of this in the morning, they may be experiencing a Sleep Terror.

What causes them?

Nightmares tend to occur in the same stage of sleep when you dream. This is known as dreaming sleep or REM sleep. REM stands for Rapid Eye Movement. In REM sleep normal dreams occur. This may play a part in how we remember and process information that we took in during the day. In a child, REM sleep may be more intense. Their imaginations may be more vivid too. This may lead to some of their dreams causing high levels of fear or confusion. In adults, nightmares are far less common. But they can still happen as a result of stress or trauma (see Post Traumatic Stress Disorder and Sleep). People with a mental illness e.g., schizophrenia, may have them as well. There are other things that can set them off too such as sickness, medicine and drugs.

How common are they?

10% to 50% of children have them. The number of adults who have nightmares is much less, from 2.5% to 10%.

How do they affect people?

Nightmares wake you up suddenly. This can make it hard to go back to sleep. If they happen a lot, you might not get enough sleep at night. A few people get so scared of nightmares that they try to avoid sleep. This can affect your mood during the day. You may feel anxious and depressed. This is especially so with nightmares due to trauma.

How can nightmares be dealt with?

In a child, they tend to just be part of growing up (i.e., not due to any major trauma). If so, the parents should simply reassure the child after a nightmare. With time they should go away. In adults there are ways to treat them such as counselling as well as methods to teach how to change the nightmare (e.g., learning to change the story line). There are also medicines that make dreams less intense or occur less often. These work both with nightmares due to trauma and other types. Teaching how to control dreams (e.g., story line alteration) works quite well in adults and even better in children.

What could you do to help?

There are ways to make nightmares happen less often. You should be sure to relax enough in the hours before bed and keep regular sleep and wake hours (see Sleep Hygiene: Good Sleep Habits). Try to reduce overall anxiety. Avoid alcohol. Parents can make sure that your children have some quiet time before bed.

Where and when should you seek help?

If you or your child keep having nightmares and this is having an impact on wellbeing (e.g., not getting enough sleep at night, being in a bad mood during the day) then you should talk to your GP. If the nightmares are from trauma, illness (physical or mental), medicines or drugs you could speak to your doctor about these issues.

What might your doctor do?

Your doctor can refer you to psychologist or sleep specialist. From them, you can get treatment to control your nightmares as well as information to help you sleep more soundly. They may also train you on how you can change what happens in your dreams to make them less threatening or frightening. If your nightmares are due to trauma in your life, you should get counselling for this. There are also paediatric sleep specialists or child psychologists who can treat children.

Download a PDF of this Fact Sheet

Other useful links: