It devotes about a half-page to tattoos and body piercing. But it does not cover shifts in adolescents' biological clocks that prompt them to stay up later and thus need to sleep later, and to need more sleep than younger children. At a time when high schools across the nation are exploring the possibility of starting later to accommodate teenagers' sleep needs, this is a significant omission. Indeed, this topic is an evolving and important one on which parents would welcome a balanced overview from a reliable source. In the chapter on sleep and sleep problems in adults, the most thorough report focuses on sleep apnea, with useful illustrations explaining what goes wrong, what causes snoring, and how treatment with continuous positive airway pressure helps.
Brief reports describe insomnia, narcolepsy, restless legs, and other disorders.
The Health in Seniors chapter offers sleep hygiene advice for older persons, and advises against using sleeping pills. In fact, people taking medications that suppress REM sleep often report sleeping better. Rotating on successive days in either direction would be onerous. In the U.S. workers typically spend five to seven days on a shift. In Europe, workers may rotate every two or three days, and then get several days off.