Nightmares typically feature fear or horror, and/or the sensations of pain, falling, drowning or death.  Nightmares can be so stressful as to suddenly wake the sufferer in a state of distress, which may prevent falling back to sleep for some time.

Nightmares may be a way to relieve the pressures of the day.  Nightmares usually begin before the age of 10 and are considered a normal part of childhood, unless they significantly interfere with sleep, physical development, or psychosocial development.  Nightmares are not real and do not predict the future or cause bad things to happen.  Nightmares are most evident between the ages of 3 to 5 years — the peak age when children talk about their fears.  Nightmares are a normal part of development.  Nightmares can occur throughout life, but tend to decrease with each passing year.

While you sleep, your brain doesn’t just turn off.  About every 90 minutes your brain switches between non-REM sleep and REM sleep.  The longest periods of REM sleep occur towards morning.  Nightmares can be so stressful as to suddenly wake the sufferer in a state of distress, which may prevent falling back to sleep for some time.

Occasional nightmares are commonplace, but recurrent nightmares can interfere with sleep and may cause people to seek medical help.  A nightmare is a dream occurring during rapid eye movement (REM) sleep that results in feelings of inescapable terror, fear or extreme anxiety.  REM sleep begins with signals from the pons, an area at the base of the brain.

One study determined that REM sleep affects learning certain mental skills.  Alcohol robs people of deep sleep and REM sleep, keeping them in the lighter stages.  Smokers tend to sleep very lightly and often wake up in the early morning due to nicotine withdrawal.

Extreme heat or cold may disrupt sleep or prevent you from falling asleep.  Frequent nightmares can lead to a fear of going to sleep, restless sleep, and daytime sleepiness.  Hypersomnia can include long periods of sleep (10 hours or more at a time), excessive amounts of deep sleep, and difficulty staying awake during the day.

Sometimes it helps to keep a dream journal, a notebook in which you describe the dreams you can recall.  Stressful things that happen during the day can turn dreams into nightmares.

Recurring nightmares happen because if you continue to worry about the same thing every day you’ll continue to have the same bad dreams night after night.  In fact, scientists have had success in controlling dreams.  They soon discovered that the strange, illogical experiences we call dreams almost always occur during the REM part of sleep.

A doctor can determine whether your nightmares are the result of a physical condition.  Some kids “rewrite” their nightmares by giving them happier outcomes.  Although it is normal to have a nightmare once in a while, there are some techniques you can try to get nightmares under control.  Some studies estimate that as many as 50% of children aged 3-6 years have nightmares that disturb both their sleep and their parents’ sleep.