How Much Sleep Do You Need?

The number of hours of sleep you need to stay healthy and alert differs according to your gender and age.

Sleep is key to your physical health and emotional vitality, but just how many hours of sleep you need depends on your age, your stage of development, and your gender.

“Sleep is important for mental function: alertness, memory consolidation, mood regulation, and physical health,” says Phyllis C. Zee, MD, PhD, professor of neurology and director of the Sleep Disorders Center at the Northwestern University Feinberg School of Medicine in Chicago.

Too few hours of sleep or poor sleep could pave the way to a myriad of emotional and physical problems, from diabetes to obesity, explains Dr. Zee. “In fact, data shows that with sleep loss, there are changes in the way the body handles glucose, which could lead to a state of insulin resistance (pre-diabetes),” says Zee. “There is also evidence that lack of sleep alters appetite regulation, which may lead to overeating or food choices that can also contribute to overweight and obesity.”

Your Sleep Needs Change Over the Years

How much sleep you need to stay healthy, alert, and active depends on your age and varies from person to person — most adults need seven or more hours of sleep per night.

“The amount of sleep needed varies among individuals, but the data supports an average of seven to eight hours,” says Zee. “Chronically lower than six hours or more than nine hours in adults has been associated with poorer cardiometabolic health.”

Here’s a snapshot of the daily hours of sleep people need at the different stages of their lives:

  • Infants (younger than 11 months): 14 to 15 hours of sleep
  • Toddlers: 12 to 14 hours of sleep
  • Preschoolers: 11 to 13 hours of sleep
  • Children: 10 to 11 hours of sleep
  • Adults: 7 to 8 hours of sleep (adolescents need a bit more)
  • Older adults: 7 to 9 hours of sleep

Gender Affects Sleep Patterns

Although most men and women need about seven to eight hours of sleep per night, their sleep patterns are generally different. Women often sleep more than men and experience a lighter sleep that is more easily disrupted. Many women have undiagnosed sleep disorders.

Problems that can disrupt women’s sleep include depression, major life events (such as divorce), pregnancy, hormonal changes related to menopause, sleep disorders (i.e., obstructive sleep apnea and restless legs syndrome), and medical problems like arthritis, back pain, and fibromyalgia.

Research shows that men often lose sleep over job-related stress. Men also tend to take sleep for granted and stay up longer than they should. Today, helping take care of the kids and keeping up with the household chores only adds to the pressure on men.

Additional stressors that cause men to lose sleep include life issues (regarding marriage/divorce, children, employment, money), medical problems like epilepsy and heart disease, sleep disorders, substance abuse, and depression.

If you believe you need professional advice about your lack of sleep, a good idea is to maintain a sleep diary for about a week. This will help your doctor get an accurate picture of your sleep history. Your doctor might recommend prescription medication, a device to keep your air passageways open, or a weight-loss plan, based on your individual symptoms and needs.

By Clare Kittredge – Medically reviewed by Lindsey Marcellin, MD, MPH