As you age your body produces lower levels of growth hormone, so you'll likely experience a decrease in slow wave or deep sleep. When this happens you produce less melatonin, meaning you'll often experience more fragmented sleep and wake up more often during the night. As your circadian rhythm (the internal clock that tells you when to sleep and when to wake up) changes, you may also find yourself wanting to go to sleep earlier in the evening and waking up earlier in the morning.
Common Problems in Elder people:
Insomnia is one of the more common sleep problems in the elderly.
Other sleep disorders, such as narcolepsy or hypersomnia, can also occur.
Sleep apnea, where the breathing stops for a time during sleep, can cause severe problems.