Sleep & Aging
Middle-aged and elderly people tend to spend less time in deeper sleep than younger people. In addition, the average total sleep time increases slightly after age 65 as do reports of difficulty falling asleep. One study found that after 65, 13 percent of men and 36 percent of women reported taking more than 30 minutes to fall asleep.
What causes this difficulty? The elderly generally secrete lesser amounts of certain chemicals that regulate the sleep/wake cycle. Both melatonin (a substance produced by the pineal gland that promotes sleep) and growth hormone production decrease with age.
There are also changes in the body temperature cycle which occur with age. These factors may cause, or be a consequence of, sleep problems. In addition, a decrease in exposure to natural light and a change in diet may exacerbate sleep difficulties. Some researchers theorize that daytime inactivity (lack of exercise) and decreased mental stimulation may also lead to the "aging" of sleep.
Falling asleep isn't the only difficulty older people may face at night. Sleep also becomes more shallow, fragmented and variable in duration with age. The elderly wake more frequently than younger adults. Recent research suggests that the aging bladder can contribute to this. Daytime sleepiness follows.
Persistent trouble falling asleep at night or frequent drowsing by day is not normal or inevitable with age.
Sometimes, age-related changes mask underlying sleep disorders. For example, sleep apnea, a breathing disorder, is more common in the middle and elder years. The repeated awakenings caused by a literal lack of breath lead to daytime sleepiness.
How to tell whether daytime drowsiness is a result of a sleep disorder, sleep deficit or depression? Consult a sleep specialist.