• Between 50 and 70 million Americans of all ages have sleep-related problems.
  • Sleepy drivers cause an estimated 20% of car crashes, resulting in thousands of deaths and injuries.
  • A study of 70,000 nurses showed those sleeping 5 hours or less a night had a 45% greater risk of developing heart disease after 10 years than those sleeping 8 hours.
  • Scientists know that if people do not get enough sleep, their brains will not work properly, they will feel terrible, and they may not be able to accomplish complex tasks.
  • Healthy sleepers experience brief awakenings, up to 5 an hour, though they will not remember these arousals.
  • All humans with intact brains dream, usually 3 to 5 times per night.

Meir Kryger is a professor in the Yale School of Medicine and chief editor of the most widely used sleep medicine textbook. According to him, seven to nine hours of sleep is adequate for most adults. After going over the sleep needs of those at different stages of life, the author looks at a variety of women's sleep problems and the differences in the body clocks between night owls and morning larks.

Dr. Kryger has treated more than 30,000 patients, and he shudders over the disastrous consequences of misdiagnosis and lack of treatment. In a section titled "Can't Sleep, Can't Stay Awake," he covers insomnia, restless leg syndrome, sleep apnea, narcolepsy, and fear of sleeping before moving on to medical conditions, psychiatric disorders, and medications that contribute to sleep disorders.

Mysteries abound in regards to sleep but this book lives up to its potential with a lively and practical overview of the complex subject.