Sleep apnea is the condition of interrupted breathing while asleep. "Apnea" is a Greek word meaning "want of breath."
Clinically, sleep apnea, means cessation of breathing during sleep.
The upper air passages become blocked during sleep, causing the individual to arouse, though not completely wake up, as many as 300 to 400 times during the night.
Obstructive Sleep Apnea
Periodic obstruction of the upper airway during sleep occurs in about 1 to 4 percent of the population and is more prevalent in men than in women.
Narrowing of the nasopharyngeal dimensions, obesity and use of sedative substances, particularly alcohol, are the chief contributing factors to the development of obstructive sleep apnea. Obstructive sleep apnea causes periodic disruption of sleep, contributing to subsequent daytime sleepiness.
Narcolepsy is a neurological disorder whose main symptom is uncontrollable, excessive sleep, regardless of the time of day or whether the person has had enough sleep during the previous night.
The other features of this disorder can include brief episodes of muscle weakness or paralysis caused by laughter and anger (cataplexy), paralysis for brief periods upon awakening from sleep (sleep paralysis), and dreamlike images at sleep onset (hypnagogic hallucinations).
Insomnia is the commonly experienced difficulty in falling asleep, and particularly appears in elderly. Its causes may be physical or psychological and it may occur regularly or only occasionally.
Patients complain of difficulty with sleep onset and sleep maintenance. The insomnia usually begins during a period of stress and becomes behaviorally perpetuated, hence the term "learned" or "conditioned" insomnia.
Patients anticipate bedtime with dread and apprehension. They tend to be performance-oriented and perfectionistic, often interpreting each night of sleeplessness as a personal failure. Although these patients feel anxious and frustrated at bedtime and on awakening during the night, they are generally not anxious, and their sleep may be much improved when they are away from home.
Primary snoring is defined as loud, disruptive upper airway breathing sounds occurring nightly during sleep, without episodes of apnea or hypoventilation. Snoring is associated with increased risk of hypertension, stroke and myocardial infarction.
Complaints of pauses, gasps, chokes and irregular respiration indicate a need for polysomnographic studies to rule out sleep apnea. Snoring may worsen or sleep apnea may emerge with advancing age, increasing weight gain or use of CNS depressants, particularly alcohol.
Restless Legs Syndrome and Periodic Limb Movements of Sleep:
Periodic limb movements increase markedly in patients over age 60. Patients may complain of difficulty with sleep onset, sleep maintenance or excessive daytime sleepiness.
Independent, rhythmic curling or jerking of the feet or legs about every 30 seconds characterizes periodic limb movements. Restless legs syndrome is described as a "creeping, crawling" sensation deep within the muscles of the legs or thighs that creates an irresistible urge to move the legs.
Bedwetting or Sleep Enuresis:
Primary nocturnal enuresis in pediatrics is viewed as continuous from infancy, with children bedwetting from once or twice a week to nightly, having never achieved urinary control. Bedwetting can occur in any stage of sleep and may be related to autonomic activation, characteristic of parasomnias.
Secondary nocturnal enuresis indicates an enuretic relapse after a period of at least 6 months of dryness. Onset can occur at any age and is thought not to be related to a parasomnia. In conjunction with a supportive environment, many behavioral techniques result in a positive outcome.