Text 2 What are and what causes sleep disorders? Medical Author: Melissa Conrad Stöppler, md Medical Editor: Charles Patrick Davis, md, PhD

8. Sleep disorders are disruptions of the sleep cycle or the quality of sleep. About 40 million Americans are believed to suffer from chronic sleep disorders, with millions more affected on an occasional basis. Doctors have defined over 70 different types of sleep disorders, but the most common sleep disorders are insomnia, sleep apnea, restless legs syndrome, and narcolepsy.

9. Insomnia is the perception of poor-quality sleep, including the inability to fall asleep or stay asleep. Because people differ in their need for sleep, there are no fixed criteria that define insomnia. Insomnia is very common and occurs in 30% to 50% of the general population. Approximately 10% of the population may suffer from chronic (long-standing) insomnia. The common symtoms of insomnia are difficulty falling asleep at night or getting back to sleep after waking during the night,waking up frequently during the night, your sleep feels light, fragmented, or unrefreshing, you need to take something (sleeping pills, nightcap, supplements) in order to get to sleep ,sleepiness and low energy during the day.

10. Sleep apnea is another common sleep disorder characterized by a reduction or pause of breathing (airflow) during sleep. Central sleep apnea (CSA) occurs when the brain does not send the signal to the muscles to take a breath, and there is no muscular effort to take a breath. Obstructive sleep apnea (OSA) occurs when the brain sends the signal to the muscles and the muscles make an effort to take a breath, but they are unsuccessful because the airway becomes obstructed and prevents an adequate flow of air. Mixed sleep apnea occurs when there is both central sleep apnea and obstructive sleep apnea. Symptoms of sleep apnea include: loud, chronic snoring, f requent pauses in breathing during sleep, gasping, snorting, or choking during sleep, feeling unrefreshed after waking and sleepy during the day, no matter how much time you spent in bed, waking up with shortness of breath, chest pains, headaches, nasal congestion, or a dry throat

11. Restless leg syndrome (RLS), also known as nocturnal myoclonus, is a type of sleep disorder characterized by uncomfortable sensations in the legs and an uncontrollable desire to move the legs. These abnormal sensations usually occur in the lower legs shortly after going to bed. During the early stages of sleep, these episodes of leg movement often last up to an hour. The abnormal sensations of RLS are quite variable. They have been described as a crawling, creeping, pulling, drawing, tingling, pins and needles, or prickly discomfort. They are not cramping in character. Common signs and symptoms of restless legs syndrome include: uncomfortable sensations deep within the legs, accompanied by a strong urge to move them,the leg sensations are triggered by rest and get worse at night, the uncomfortable sensations ,temporarily get better when you move, stretch, or massage your legs, repetitive cramping or jerking of the legs during sleepNarcolepsy is a disease of the central nervous system that results uniformly in excessive daytime sleepiness (EDS). Other primary symptoms of narcolepsy include the loss of muscle tone (cataplexy), distorted perceptions (hypnagogic hallucinations), and the inability to move or talk (sleep paralysis). Additional symptoms can include disturbed nocturnal sleep and automatic behaviors (affected persons carry out certain actions without conscious awareness). All of the symptoms of narcolepsy may be present in various combinations and degrees of severity. Common signs and symptoms of narcolepsy include: seeing or hearing things when you’re drowsy or starting to dream before you’re fully asleep, suddenly feeling weak or losing control of your muscles when you’re laughing, angry, or experiencing other strong emotions, dreaming right away after going to sleep or having intense dreams, feeling paralyzed and unable to move when you’re waking up or dozing off.Other sleep disorders include: periodic limb movement disorder, problem sleepiness, hypersomnia, sleepwalking, snoring, nightmares, and night shift work sleep disorder.