Psychology -> Sleep disorders
Sleep clinics diagnose and treat many people who suffer from sleep disorders. We may identify with some characteristics of the following disorders however, a diagnosed sufferer would find the disorder debilitating, having an adverse impact on their life.
Insomnia: This is when a person has problems getting adequate sleep. This can be a temporary or chronic problem. It may be caused by stress, depression or changes in biological rhythms.
Hypersomnia: The person experiences excessive daytime sleepiness and has extreme difficulty in awakening. The person feels drowsy during the day no matter how many hours the person has slept. This may be caused by other sleep disorders such as insomnia, narcolepsy or sleep apnea.
Sleep apnea: This is a temporary cessation of breathing during the night (can be 20 seconds or more) which deprives the person of oxygen. It is associated with snoring where the person gulps for air then settles back to sleep. This may happen hundreds of times throughout the night and can be very dangerous to the person's health.
Narcolepsy: The person has sudden uncontrollable sleep attacks where they go from being wide awake straight into REM sleep. The usual muscle paralysis of REM sleep occurs called cataplexy. This disorder can be very dangerous, especially if a sleep attack happens when the person is driving or working with machinery.
Nightmares: These occur during REM sleep and are frightening REM dreams. They can usually be remembered and usually occur during a REM episode toward the end of the night or early morning.
Night terrors: These occur during NREM sleep (stage 4) and, because the muscles are not paralysed, involve violent body movements such as thrashing about or running. The person often wakes up in a sweat and in extreme stress, unable to recall the night terror. Night terrors occur less frequently than nightmares and usually occur earlier in the night than nightmares.
Sleep walking: This occurs during the deep NREM sleep (stage 4) and hence it is difficult to wake the sleepwalker. It appears to be an inherited trait.
Sleep talking: This often accompanies sleep walking and also occurs during the deep stages of NREM sleep (stage 4). It is also thought to have a hereditary link.