How Sleep Changes Throughout Your Life

From the WebMD Archives


What Affects Your Need for Sleep

In addition to age, your sleep needs change due to:

  • Gender
  • Genetics
  • Internal clock (circadian rhythm)
  • Quality of sleep
  • Recent lack of sleep

Gender. Women undergo more sleep changes and challenges than men because of their reproductive hormones. Women who are pregnant need more sleep in the first trimester. Pregnant women also struggle to get enough sleep because of heartburn, snoring, and uncomfortable sleep positions. Arand says that once women become mothers, they tend to have problems sleeping because their children wake them up or cause them to worry.

Later in life, as women enter menopause, they face new sleep challenges. These come from drops in hormone levels, hot flashes, night sweats, and insomnia. “Women tend to report difficulty with insomnia more than men,” Arand says. “We don’t know if it’s a social issue or if women are more willing to report it than men.”

Genetics. Genes may play a role in some sleep disorders, such as narcolepsy and insomnia. There hasn’t been enough research to know how your family tree affects your sleep. Arand thinks that the treatments for sleep problems will work despite any genetic flaws.

Biological clock. Each of us has an internal clock, which makes some people “night owls” or “early birds.” A process in the brain called circadian rhythm controls this. This process influences when we wake up and go to sleep. It also determines how sleepy and alert we are. (It’s because of teenagers’ circadian rhythms that they’re geared to stay up later and to wake up later.)

Our internal clock makes us drowsy naturally between midnight and 7 a.m. and between 1 p.m. and 4 p.m. [As people age, changes in circadian rhythm eventually make older people feel sleepy earlier in the evening and wake up earlier in the morning.

Quality of sleep. The type of sleep people get changes most between ages 19 and 60. Children and teens experience a lot of deep sleep, which is believed to restore the body. This also fuels their growth. Arand says that children spend about 50% of their night in deep sleep. By the time they’re 20 years old they get half that amount. She said some people as young as 40 may lose the ability to go into that restorative sleep. Older people spend little time in that sleep stage. As a result, they are more easily awakened.