If you're reaching middle age and you've noticed you're sleeping less at night - don't worry, it's natural, a new research study has discovered. But it's not so natural to feel sleepy during the day if you're elderly. As we get older, our 'sleep need' decreases. While younger people may need up to eight hours of sleep, older adults sleep around 20 minutes less, while the elderly slept around 23 minutes less than that, researchers from the University of Surrey have found. Older people also tend to wake up more during the night, and this is all part of the pattern of healthy ageing, the researchers found. But, conversely, elderly people who feel sleepy during the day may be suffering from a sleeping disorder and are not getting sufficient sleep at night. (Source: Sleep, 2010; 33: 211-23).