The final physical element that is important for overall wellbeing is sleep.

Lack of sleep is associated with disruptions in mood, thinking, concentration, memory, learning, vigilance and reaction times (Hillman & Lack, 2013). Sleep is considered an important diagnostic criteria for depression, while people who are good sleepers report better quality of life than those who suffer from insomnia (Nes et al., 2005).

The following facts about sleep come from the Sleep Health Foundation.

  • Sleep need varies. Different people need different amounts of sleep. Eight and a quarter hours is the average for adults. Some people can cope very well with much less and some need much more every night.
  • Sleep is an active state. We used to think that everything shuts down when we sleep. But over the last 60 years scientists have discovered that our brains are very active while we sleep. In fact, some parts of the brain use more oxygen and glucose while asleep than when awake.
  • Deep sleep happens first. The first three hours of sleep have the deepest stages of sleep (Slow Wave Sleep). Later on in the night we have more of the sleep stage with vivid dreams (Rapid Eye Movement Sleep, REM sleep).
  • Sleep changes in cycles. Sleep changes across the night in cycles of about 90 minutes. There is REM (dreaming) sleep in every cycle, even if only for a short time. We also have very brief arousals many times across the night. We are not aware of most of these arousals and we forget most dreams.
  • A body clock affects our tiredness. The timing of our need for sleep is based on two things. The first is how long we have been awake. The second is our body clock. If we stay awake all night we will feel more tired at 4am than at 10am. Scientists call the time between 3am and 5am the ‘dead zone’. It’s when our body clock makes us ‘dead’ tired.
  • Falling asleep can be hard. You cannot make yourself fall asleep – just like you can’t digest your food faster. Sleep onset is not something we can control. We can only create the right conditions for sleep – both in our minds and in our environment.
  • Lack of sleep can bring you down. Some people cope with a lack of sleep much better than others. But people who are very sleepy lose concentration easily and experience mood changes, such as feeling more depressed and irritable.

How much sleep do I need?

  • It is recommended that adults get between 7 to 9 hours of sleep per night.
  • However, for some people, their normal sleeping pattern may be around 5-6 hours per night.
  • It is not recommended that adults sleep less than 6 hours or more than 10 hours per night.

If you experience any problems with your sleep, or would like more advice on your sleeping patterns, please contact your doctor or pharmacist. 

Further information may be found on the Sleep Health Foundation website at


There are many things that can be done to have a better night’s sleep. It is not good to frequently change the times you go to bed and get up.

  • The hour before going to bed should be used to wind down and do more relaxing things
  • Meals should be timed to avoid going to bed on a full stomach, but not hungry either
  • If you are not asleep after 20 minutes in bed, go to another room until you feel tired again and then go back to bed
  • Many poor sleepers spend too long in bed
  • Don’t have things in the bedroom that distract you from sleep
  • Getting sunlight during the day will help you to sleep better at night
  • Most adults need 7-9 hours of sleep a day. This stays the same even in old age
  • Naps in the evening can make it hard to sleep at night