People with sleep paralysis are not able to move their body or limbs either when falling asleep or waking up. Brief episodes of partial or complete skeletal muscle paralysis can occur during sleep paralysis. Sleep paralysis can run in families, but the cause of sleep paralysis is not known. This disorder is not harmful, but people experiencing sleep paralysis often are fearful, because they do not know what is happening. An episode of sleep paralysis often is terminated by sound or touch. Within minutes, the person with sleep paralysis is able to move again. It may occur only once in your lifetime or can be a recurring phenomenon.
Impaired Sleep-Related Erections
This disorder occurs among men who are unable to sustain a penile erection during sleep that would be sufficiently rigid enough to engage in sexual intercourse. Men usually experience erections as a part of REM sleep, and impaired sleep-related erections may indicate erectile dysfunction.
Sleep-Related Painful Erections
Erections are a normal component of REM sleep for men. In rare cases, however, erections become painful and cause a man to wake up. The treatment of sleep-related painful erections may involve drugs that suppress REM sleep (some antidepressants, for example).
Irregular Heart Rhythms
A cardiac arrhythmia -- the medical term for an irregular heart rhythm -- is a change from the normal rate or control of the heart's 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)
People with rapid eye movement (REM) sleep behavior disorder act out dramatic and/or violent dreams during REM sleep. REM sleep usually involves a state of sleep paralysis (atonia), but people with this condition move the body or limbs while dreaming. Usually, RBD occurs in men aged 50 and older, but the disorder also can occur in women and in younger people. It differs from sleepwalking and sleep terrors, in that the sleeper can be easily awakened and can recall vivid details of the dream. In the diagnosis and treatment of RBD, potentially serious neurological disorders must be ruled out. Polysomnography (sleep tests) and drug treatments also can be involved in the diagnosis and treatment of this disorder.