World Sleep Day
There’s nothing better than a good night’s sleep. It’s wonderful to wake feeling refreshed. Sleep is very important for our health. During sleep the mind refreshes and the body rejuvenates.
During sleep our mind cycles through different phases of brain wave activity. There is the REM (rapid eye movement) phase which is when we have our dreams. During this phase our muscles are paralysed so we don’t act out our dreams (except for the occasional kick from a husband who is dreaming he is playing football!). Before the REM phase is reached the mind winds down through four stages of non-REM sleep. The first stage is light sleep and sometimes you may not even think you are asleep but your muscles are relaxing and eye movements are slowing. A short “catnap” is typically this first light stage of sleep. A “powernap” is a bit longer (20 minutes) and takes you into stage 2 which is deeper sleep but still relatively light and you can be woken easily. If you don’t wake from a powernap in this stage, watch out because you are diving into deep sleep! During stages 3 and 4 our minds really chill out and brain wave activity becomes very slow - even loud noises may not wake us. It is during deep sleep that our bodies repair muscles and tissues, growth is stimulated (remember growing pains at night as a child), the immune system is boosted, and energy is built up. REM sleep is very important too. During this phase the mind processes all the information from during the day so you can remember, understand and think clearly the next day.
Cycles of REM and deep sleep repeat about every 90 minutes. When we wake during the night it is usually in between these cycles when sleep lightens back into REM and this is why we often wake during or after a dream.
A lack of sleep can have a multitude of untoward effects on our mental and physical health. Decision making and reasoning skills are impaired, and anxiety and depression can occur. Immune system dysfunction can result in infective illness (eg catching a cold when you are tired and run down), inflammatory and autoimmune disorders, and possibly even cancer.
Changing time zones affects our body clock which is influenced by the day-night cycle. For each hour in time zone shift, it takes a day for our brain to adjust.
Today’s devices – phones, tablets, computers – can affect our sleep-wake cycle (circadian rhythm). The blue-light screen makes our brain think it is daytime and suppresses melatonium secretion (which normally peaks at night and helps us sleep). If your device has a “Night Shift” function which makes the screen have a red tinge rather than blue at night, use it, it helps!
- Using these devices to check emails, Instagram, Facebook etc provides a further stimulus to keep us awake.
- Caffeine and alcohol can also contribute to a poor night’s sleep.
- To help achieve a good night’s sleep, aim to reduce such stimulation.
- Put your phone on silent or do not disturb (your favourites will still be able to call).
- Try to resist the urge to check social media and work.
- Do something relaxing. Take a bath, read a book or put some relaxing music on.