Parasomnias are disruptive sleep-related disorders that can occur during arousals from REM sleep or partial arousals from Non-REM sleep.

Types of Parasomnias:

  • Nightmares - Nightmares are vivid nocturnal events that can cause feelings of fear, terror and/or anxiety. Usually, the person having a nightmare is abruptly awakened from REM sleep and is able to describe detailed dream content. Usually, the person having a nightmare has difficulty returning to sleep. Nightmares can be caused by many factors including illness, anxiety or negative reactions to a medication.
  • Sleep terrors/night terrors - A person experiencing a night terror or sleep terror abruptly awakes from sleep in a terrified state. The person may appear to be awake, but is confused and unable to communicate. Night terrors last about 15 minutes, after which time the person usually lies down and appears to fall back asleep. People who have sleep terrors usually don’t remember the events the next morning. Night terrors are similar to nightmares, but night terrors usually occur during deep sleep. People experiencing sleep terrors may pose dangers to themselves or others because of limb movements. Night terrors are fairly common in children aged three to five. This sleep disorder (which may run in families) also can occur in adults. Strong emotional tension and/or the use of alcohol can increase the incidence of night terrors among adults.
  • Sleep walking - Sleepwalking occurs when a person appears to be awake and moving around but is actually asleep. Sleepwalking can be dangerous because the sleepwalker is unaware of their surroundings and can bump into objects or fall down. They have no memory of their actions.
  • Confusional arousals - Confusional arousals usually occur when a person is awakened from a deep sleep during the first part of the night. This is also known as excessive sleep inertia or sleep drunkenness. People experiencing confusional arousals react slowly to commands and may have trouble understanding questions when asked. People with confusional arousal often have problems with short-term memory, as well.
  • Rhythmic movement disorders - Rhythmic movement disorder occurs mostly in children who are one year old or younger. A child will lie flat, lift the head or upper body and then forcefully hit his or her head on the pillow. Rhythmic movement disorder, which also has been called "head banging," also can involve movements such as rocking on hands and knees. This usually occurs just before a person falls asleep.
  • Sleep talking - Sleep talking is a sleep-wake transition disorder. Talk that occurs during sleep can be brief and involve simple sounds or it can involve long speeches by the sleeper. A person who talks during sleep usually has no memory of their actions. Sleep talking can be caused by external factors including fever, emotional stress or other sleep disorders.
  • Nocturnal leg cramps - Nocturnal leg cramps are sudden, involuntary contractions of the calf muscles during the night or periods of rest. The cramping sensation may last from a few seconds to 10 minutes, but the pain from the cramps may linger for a longer period. Nocturnal leg cramps differ from restless legs syndrome (RLS) as the latter usually does not involve cramping or pain. The cause of nocturnal leg cramps is not known.
  • Sleep paralysis - People with sleep paralysis are not able to move their body or limbs when falling asleep or waking up (for a short period of time). The cause of sleep paralysis is not known. This disorder is not harmful and is often is terminated by sound or touch.
  • REM sleep cardiac arrhythmias - A cardiac arrhythmia is a change from the normal rate or control of the hearts contractions. People who have coronary artery disease and whose blood oxygen is lowered by sleep-disordered breathing may be at risk for arrhythmias, which take place during REM sleep. Continuous positive airway pressure (CPAP) treatment may reduce this risk.
  • REM sleep behavior disorder (RBD) - Rapid eye movement (REM) sleep behavior disorder causes people to act out dramatic and/or have violent dreams during REM sleep they move their body or limbs while dreaming.
  • Sleep bruxism - Sleep bruxism involves the involuntary, unconscious, excessive grinding or clenching of teeth during sleep. (It may occur along with other sleep disorders.)
  • Sleep enuresis (bedwetting) - In this condition, the affected person is unable to maintain urinary control when asleep. There are two kinds of enuresis -- primary and secondary. In primary enuresis, a person has been unable to have urinary control from infancy onward. In secondary enuresis, a person has a relapse after previously having been able to have urinary control.
  • Nocturnal Paroxysmal Dystonia (NPD) - This disorder is sometimes marked by seizure-like episodes during Non-REM sleep. Most evidence points to NPD being a form of epilepsy. Episodes of NPD typically recur several times per night.