Sleep is necessary for good health at all stages of life. While in general some changes in sleep and sleep patterns are part of normal elderly, the need for restorative sleep is not dependent on age. Normal changes to sleep patterns should not cause personal dissatisfaction with quantity or quality of sleep (Dowson et al., 2008).
Changes to sleep patterns which affect quality of sleep or disrupt a normal sleep cycle are known as sleep disturbances. It is sleep disturbances that have an adverse effect on health and quality of life. While research on sleep has traditionally examined the effects of sleep quantity, a more recent distinction incorporates the effect of sleep quality. For example, the Irish Longitudinal Study on Ageing (TILDA) survey focused on sleep disturbance as opposed to the number of hours slept.