Sleep affects virtually all areas of health. With adequate sleep (typically 7–9 hours for an adult on average), individuals feel refreshed and energetic, and overall they have a general sense of well-being. In the absence of good sleep, physical and mental health are both negatively affected. Unfortunately, sleep disturbances are common. According to the American Academy of Sleep Medicine, International Classification of Sleep Disorders, Third Edition, there are about 90 different disorders. These sleep-wake disorders can be broken down into six main categories: (1) insomnia, (2) sleep-related breathing disorders, (3) central disorders of hypersomnolence, (4) circadian rhythm sleep-wake disorders, (5) parasomnias, and (6) sleep-related movement disorders. The most common of these disorders includes insomnia, obstructive sleep apnea, hypersomnia, circadian rhythm disorders, parasomnias, and restless legs ...