Good sleep = good health

Sleeping well makes us feel better, more alert, energetic, and better able to concentrate and perform our daily tasks. Getting enough sleep each day is one of the most important things you can do for your health and wellbeing and to reduce your risk for ill-health.

Why sleep is important

It is well known that sleep is an important biological function essential for life. While we sleep many important functions take place that help the body in physical recovery and repair, support brain development, cardiac function and body metabolism, as well as support learning, improving memory and mood. Sleep is especially important for children playing an important role in growth and overall health and babies and children need much more sleep than adults.

Without enough sleep we are more likely to have problems with thinking, concentration, memory, reaction times and mood, all of which make it harder to perform our daily tasks and increase the risks of mistakes and accidents. Regular insufficient or poor sleep contributes to long-term health problems such as;

  • Obesity
  • Type 2 diabetes
  • Cardiovascular disease
  • Poor mental health.

For more information visit the Harvard sleep and disease risk page. 

How sleep works

Sleep is a state of reduced consciousness, but one which we can be easily wakened. When we sleep our brains remain active, although activity levels vary throughout the course of sleep along with other physiological functions, such as body temperature, breathing and heart rate.

Sleep drive and our body clock 

Our sleep is controlled by two interacting systems:

  • Homeostatic sleep drive processes which balance out time awake with periods of sleep.In other words, when we have been awake for a long period, this process ensures we feel sleepy and helps us sleep long enough to make up for the time we are awake.
  • Body Clock is the name often used to refer to Circadian Rhythms. Circadian rhythms are created by our central nervous system and control a lot of our biological process such as sleep, as well as body temperature and hormone activity. Our circadian rhythms are also synchronised with the 24-hour cycle of light and dark resulting in our normal pattern of night-time sleep.

If our circadian rhythms are disrupted it can interfere with our sleep. For example, Jet Lag occurs when our circadian rhythms are disrupted by long-distance flying.

Sleep cycles 

Sleep is divided into different periods of light and deep sleep across the night. These occur in cycles of about 90 minutes. Each cycle includes periods of non-REM sleep, ranging from light to deep sleep, and REM (Rapid Eye Movement) sleep when our brains are more active and dreams occur. 

Sleep cycles are different for older and younger people. Sleep cycles can be affected by a number of things such as disruption to your body clock (circadian rhythms), too much day-time napping, stress, exercise or too much exposure to bright light prior to usual bed time.

For more information visit the Harvard sleep patterns page. 

Further information