It is widespread. Sleep disorders affect as many as one-third of American adults. This includes 40 million people with chronic sleep problems and another 20-30 million with intermittent difficulties. Millions more are sleep deprived due to the demands and stresses of everyday living, and may be at risk for sleep difficulties since stress is a leading cause of insomnia. In women, physiological factors such as the menstrual cycle, pregnancy and postpartum, and menopause commonly interfere with sleep throughout women's lives. A government commission recently reported that sleep difficulties may affect more than 40% of women over the age of 40!