Sleep in the elderly. What is normal?

Sleep is a basic biologic function that changes with normal aging and in many pathologic states. Some of the changes with aging are so profound that it is difficult to separate normal aging from disease. The problem is made worse by the difficulty of recognizing many common sleep disorders. Complaints of poor sleep or daytime somnolence are common in all adults but are more prevalent in elderly individuals. This article addresses normal sleep and the changes expected with aging, and reviews the more common sleep diseases in the elderly population, such as insomnia, sleep-disordered breathing, periodic limb movements of sleep, and the rapid eye movement sleep-behavior disorder.