More than 20 million women can't sleep at night or have trouble staying awake and alert during the day. Unfortunately, most of these women don't realize they have a sleep disorder. Although sleep disorders affect both men and women, sleep disorders among women are more prone to misdiagnosis and mistreatment. Women experience different symptoms of sleep disorders than men and the onset of a sleep disorder occurs for different reasons than do men's. Hormones, hormone replacement, different ages and stages of a women's life including pregnancy, new motherhood, perimenopause, menopause, menstrual cycles and the sleep disorders of children and sleep partners make a book like "A Woman's Guide to Sleep Disorders" necessary for women and their doctors. Women take twice as many drugs as men, many of which cause sleep disorders.Women are more likely to experience RLS (Restless Leg Syndrome) and other sleep movement disorders than men. Because of menstrual cycles, more women are iron deficient, which causes sleep disorders. Women are diagnosed and treated for depression more often than men are and some of the anti-depressants prescribed to these women cause sleep disorders as does the inability to sleep because of depression. Research has shown that insomnia is more common in women than in men (64 per cent vs. 50 per cent). Dr. Kryger's book goes beyond the issue of sleep deprivation in women that is covered in other sleep books. It is designed to be a health book about what women (and their doctors) should know about recognizing whether their sleep problem is an actual disorder, what causes it, and how to medically treat the disorder. A special section on the role that hormones and hormone replacement therapy play in sleep disorders is included.