How sleep changes as you grow older
Why is it that the launch of the space shuttle won’t awaken your child, but the sound of your spouse’s cough snatches you out of your peaceful slumber? It’s because the quality of your sleep changes as you age.
Infants need 16 to 20 hours of sleep broken up over the course of the day. As you mature, your sleep becomes more consolidated, with adults typically requiring seven to nine hours of sleep.
And once you hit middle age, you may start noticing that you can’t sleep as soundly or continually as you once did as a child.
Another significant change affecting sleep in older adults is that there is less deep sleep. It is a common misconception that as you age, you should come to expect poorer sleep quality. While many people do sleep poorly for various reasons, it is not simply due to age.
Here are the most common age-related sleep changes:
Less deep sleep
There are five stages of sleep: 1, 2, 3, 4 and REM. Stages 3 and 4 are the deep-sleep stages where your brain waves slow to allow for your body to undergo maintenance activities such as tissue repair and memory consolidation. This is the sleep you need to feel rested. Each night we cycle through all five stages of sleep, and each cycle lasts between 90 and 120 minutes. As you age, your body changes and you spend less time in the deeper stages of sleep and more time the lighter stages.
More fragmented sleep
Since you spend more time in lighter stages of sleep, it is easier for you to be awakened from environmental influences such as noise, light and temperature. Older adults also spend less time in dream sleep because of changes to their biological clocks, which changes sleep structure.
Tendency to fall asleep and wake earlier
Clinically, this is called phase advancement. This is the opposite of what occurs in teenagers who tend to have their peak energy late in the evening.
Adults older than 65 typically slow down in the early evening. They have a natural drive to go to sleep earlier, around 8 or 9 p.m., for example, and wake in the wee hours of the morning.
Less melatonin production
Melatonin is the hormone that drives your body clock. It tells your brain and body when it is time to sleep and wake up. Melatonin is secreted in the brain at nighttime when it is dark, and it shuts off in the morning with the light. As we age, we begin to produce less melatonin, which makes it harder to fall asleep at night.
More medical problems
Unfortunately, as you age, you are more prone to health challenges. It is common for an adult older than 60 to take several medications a day for various problems. The medical problems, especially ones that cause pain, and the medications used to treat the problems can interfere with sleep.
Getting old can mean losing your usual good night’s sleep and result in daytime sleepiness and the need for naps. Although you can’t control these age-related sleep changes, you can minimize the damage by understanding the changes and adapting your sleep schedule to accommodate the earlier bedtime.
Additionally, continuing to exercise and exposing yourself to sunlight during the day can lessen the impact of the changes to your body clock and help you sleep more peacefully and efficiently.
Dr. Tracey Marks is an Atlanta-based psychiatrist/psychotherapist who specializes in better sleep. Her website is www.masteryoursleepbook.com.