How much sleep is enough?

Did you know?

Women who regularly get fewer than 7 hours of sleep each night may have a higher risk of developing high blood pressure.

Some people are nightingales, rising early in the morning, while others are night owls, staying up till all hours. Body clocks differ between people and can change as we age.

Teenagers tend to sleep late, and getting up early for school or work can put them at a high risk of being chronically sleep-deprived. Adults tend to sleep earlier, and by around age 50, most start to experience lighter, more disturbed sleep, with increasing sleepiness during the day.

Whatever our preferred sleep times are, most adults need between 7 to 9 hours of sleep in a 24 hour period. If you’re feeling sleepy during the day, you may not be getting enough sleep. After several nights of getting less sleep than you need, your body builds up a ‘sleep debt’ that you have to ‘repay’ by sleeping longer than usual.

Your sleep requirement changes throughout your life – newborns sleep 16-18 hours a day and pre-school children sleep 10-12 hours. Older children and adolescents need at least 9 hours’ sleep a night, although you may have trouble convincing them of this!

Sleep times by age

Teenagers need lots of sleep

Getting enough sleep is especially important for growing teens. The foundation offers these reasons for getting enough zzzs:

• Lack of sleep can cause problems with learning, memory and concentration.
• Without enough sleep, teens may be more susceptible to acne and other skin problems.
• Fatigue can cause aggression and irritability toward others, which can cause problems with family, friends and relationships.
• Lack of sleep can lead to overeating, and eating more unhealthy foods.
• Fatigue can make teens more likely to use nicotine and caffeine to stay awake.
• Tired teens may be more susceptible to illness.

Girls can find it hard to sleep

Natural changes in the body may keep teenage girls wide awake long after they're supposed to be asleep, according to Girl Power, an American national public education campaign sponsored by the US Department of Health and Human Services.

So, what can teen girls do to make it easier to fall asleep? Girl Power suggests keeping regular bedtime hours, relaxing before going to bed (avoid reading scary novels), playing sports in the afternoon but not right before bed, and avoiding foods and drinks that contain caffeine.

Women’s sleep patterns change

Women’s changing levels of hormones, like oestrogen and progesterone, can be responsible for different sleep patterns throughout each month and over her lifetime.  Periods, pregnancy and menopause can all affect how well you sleep, and having an understanding of how these things can interact with other factors, like lifestyle and environment, can help achieve quality sleep. 

• Exercise can lessen the effects of premenstrual tension (PMS) and helping you sleep more deeply. Make sure you finish exercising at least three hours before you go to bed.
• Avoid foods and drinks high in sugar, caffeine and alcohol before bedtime.
• Quit smoking - nicotine can lead to broken sleep and raises your risk of getting cancer and heart disease.
• Plan your meal times so you don’t overeat late at night, and cut back on drinks before you retire.
• Make your bedroom a relaxing haven – keep it dark, cool and quiet. Make sure bed linen and pillows are comfortable.

Seniors sleep less soundly

As we pass from young adulthood to midlife, the time we spend in deep sleep falls and the time we spend in light sleep increases. And as we age further our sleep tends to be interrupted by periods of wakefulness, meaning that we lose increasing amounts of both REM sleep and light sleep. Elderly people also fall asleep earlier in the evening than younger people and wake up correspondingly earlier.

Although many elderly people have sleep difficulties, these are not necessarily a normal part of ageing. Insomnia may be due to medical conditions or medicines that disrupt sleep, so if you’re having trouble sleeping – at any age – it’s best to see your doctor for a thorough evaluation.