The changes that aging brings tend to come upon us unnoticed at first, like the passing of the seasons. Slowly, over time, we become aware that our eyesight is less keen or our hearing less acute. In the same way, our experience of sleep is altered. It's not that our sleep needs decline with age. In fact, research demonstrates: Our Sleep needs remain constant throughout adulthood. Most of us still require the same seven to nine hours of sleep a night we always did. However, a good night's rest may prove more elusive as we grow older. Lifestyle changes and behavioral practices may play their part. Daytime naps may make us less tired at bedtime. Poor sleep habits may have become entrenched; we may associate our bed with television or reading, not sleeping. Stress and bereavement may lead to early awakenings or interrupted sleep. And in the silence of our bedrooms, the bark of a neighbor's dog or a passing siren may trouble us more than when we were younger. How Sleep Changes 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. The Impact of Sleep Problems Sleep Deprivation has measurable negative effects on performance and physical and mental health: Reduced energy, greater difficulty concentrating, diminished mood, and greater risk for accidents, including fall-asleep crashes. Work performance and relationships can suffer too. And pain may be intensified by the physical and mental consequences of lack of sleep.