Typical hypnograms for children, young adults, and elderly

Note that in all three cases, the majority of deep, slow-wave sleep occurs during the first half of the night, and the majority of REM sleep occurs in the latter half of the night. Elderly sleep is shallow and fragmented—it exhibits less slow-wave sleep, shorter REM periods, and more frequent periods of wake. Children have a long, restorative period of delta sleep during the first sleep cycle, and another early in the morning.

Current thinking is that the shallow fragmented sleep of the elderly is more a function of other health problems than a sleep problem per se. Elderly persons in excellent health do not exhibit shallow, fragmented sleep. Those with multiple health problems, do.