Circadian rhythm

Another common age associated sleep change relates to the circadian rhythm of the typical sleep period. Although exceptions exist, elderly persons tend to go to sleep earlier in the evening and to awaken earlier in the morning. Early morning awakening is a common complaint in the elderly.

Some people find it annoying to awaken spontaneously at 4:30 a.m. instead of at 6:30 a.m. In these persons, if the onset of evening sleeps is not correspondingly earlier, sleep deprivation and excessive daytime sleepiness may result.

Daytime napping may compound the problem by reducing the drive for sleep at the usual bedtime hour, resulting in delayed sleep onset and a further decrease in the duration of nighttime sleep.