While the actual amount of healthy sleep necessary for each individual may vary, in the absence of alarms and lights, the natural length of sleep appears to be just over eight hours.
As we get older, we don’t need less sleep, but we often get less sleep. Older people have more fragile sleep and are more easily disturbed by light, noise, and diet. One study found that after 65, 13% of men and 36% of women reported taking more than 30 minutes to fall asleep. Decreased exposure to natural light and a lack of exercise and mental stimulation may be among the culprits. Sleep becomes more shallow, fragmented and variable in duration. An aging bladder may also contribute to the problem.
One factor thought to contribute to excessive sleepiness in the elderly is frequent chronic pain. Nighttime pain sufferers in the over 50 age group, who experience difficulty sleeping, lost an average of 2.2 hours of sleep per night, over 10 nights a month. The good news is that persistent trouble falling asleep at night or frequent drowsing by day is normal or inevitable with age.