About Sleep

We spend approximately one third of our lives asleep. This time plays a large role in how much energy and enthusiasm we have for the other two thirds of our lives. After a good night's sleep we wake up feeling refreshed and alert. The quality of our sleep affects the way we perform the next day, and the way we look and feel. Not sleeping well can have a big impact on our overall quality of life if it goes on for an amount of time. Memory, learning and logical reasoning are all things which can be impaired if you are not getting regular good quality sleep. There is research to suggest that sufferers of chronic insomnia are more likely than others to develop some kinds of psychiatric problems and general illness.

In general, a healthy adult requires between 7-9 hours sleep, however some people are able to function on as little as 6, or need as many as 10. If you have trouble staying awake during boring situations it is a sign that you are not getting as much sleep as you need. Irritability and difficulty concentrating or remembering things are other common signs that you are not getting enough sleep.

If you are not getting the amount of sleep your body requires you could build up a sleep debt. Even if you sleep well for a few nights consecutively, if you have not caught up on the sleep which you have missed out on you will continue to feel sleepy during the day. It's important to catch up on missed sleep to get back into a regular healthy sleeping pattern. Sleep deprivation resulting from sleep debt which hasn't been paid back could be linked to health issues such as weight problems, high blood pressure, and depression.

What happens when we sleep?

When we sleep our body rests, however our brain remains active, getting recharged and controlling bodily functions such as breathing, growth and repair. There are two states of sleep, NREM (non rapid eye movement) and REM (rapid eye movement).

Sleep occurs in a recurring cycle of approximately 90 to 110 minutes. NREM sleep has four stages, starting with drowsiness and developing into deep sleep. Being woken is more difficult during deep sleep, and this is when the most restorative effects of sleep occur. During REM sleep dreams occur, eyes dart back and forth, muscles relax and breathing and heart rate increases. REM sleep occurs through approximately 25% of the night. We have around 3-5 sleep cycles each night.

Stage one; drowsiness, reduced muscle activity, awakened easily. Stage two; onset of sleep, less aware of surroundings, drop in body temperature, breathing and heart rate begin to slow down. Stage three; blood pressure drops, slower breathing, relaxed muscles, tissue growth and repair, energy restored, hormones released. Stage four; rhythmic breathing, limited muscle activity, feel groggy if awoken, bedwetting, night terrors and sleep walking occur during this stage.