Sleep is a periodic state of rest for the body which is absolutely essential for its efficient functioning. Sleep gives relief from tension, rests the brain and body and a person wakes up in the morning fresh and relaxed after sleep. The amount of sleep varies within very wide limits from individual to individual.
Normally, seven to eight hours of sleep every night is adequate for most. Some do well with four to five hours because their sleep is deeper and more refreshing.
Insomnia is common among the elderly for a variety of reasons. The sleep of the elderly is often punctuated by brief periods of wakefulness during the night. In such cases it is the quality rather than the quantity which is most affected.
With age there is gradual reduction of periods of deep sleep. The older person gets roused easier. Sleep requirements also diminish with ageing. From nine hours of sleep per night at the age of 12 the average sleep needs decrease to eight hours at the age of 20, seven hours at 40, six and half hours at 60 and six hours at 80.
Other symptoms are emotional instability, loss of coordination, confusion and a lingering feeling of indifference.