What Happens When We Sleep?
Circadian rhythms differ but the sleep phase cycle is the same for us all. Circadian rhythms refer to our daily pattern of waking and sleeping and everyone’s circadian rhythm will be different. Our own circadian rhythms will be constantly changing as we grow older.
However, within a sleeping period of our own circadian rhythms, there is a definite pattern/cycle to everyone’s sleep that reoccurs roughly every 100 minutes. There are five distinct phases of each cycle. Each phase of sleep is important for optimal mental and physical health. We may go through this entire cycle (5 phases) up to 4 or 5 times each night.
Hormone exchange
To the naked eye, we appear stationary in sleep. But ‘sleep’ is a verb! It’s a very active process. During each phase of sleep a different complex exchange of hormones send important messages throughout our nervous systems. Brilliant sleep requires this exchange to be balanced and effective.
Very simply speaking, here is what happens while we sleep
- Phase 1 - our eyes close and we feel our bodies start to relax. We can still hear what is going on and are easily disturbed as we drift off to sleep. Melatonin (a sleep regulating hormone) production is stimulated by the dark and the levels of melatonin start to rise. Serotonin (commonly known as the happiness hormone) levels decrease in the lower light levels as we fall into a deeper sleep.
- Phase 2 - our breathing and pulse rates starts to slow and blood pressure drops as we fall into a deeper phase of sleep. The exchange of melatonin and other hormones becomes more active as sleep deepens.
- Phase 3 & 4 - brain waves are longer and slower and adrenalin and cortisol levels drop as our body temperature drops. This is the deepest phase of sleep and is very nourishing and rejuvenating. This restorative sleep is very important for optimal physical health.
- Phase 5 - commonly known as the REM (Dreaming) phase is important for mental health and it’s during this phase that our brains actively process the information we have received during the day and order it so we can learn and understand the world around us. During this phase breathing becomes shallower and pulse and blood pressure become irregular. We are almost in a semi- conscious state and this is the phase we remember the details of our dreams. Hormones active during this phase actually disconnect major muscles to avoid us hurting ourselves or others as we act out our dreams! Muscles may twitch as the brain processes the information it is processing.
The best sleep happens when all of these exchanges during the different phases occur as they should. If they are broken or interrupted, the quality of sleep may be affected.
Through all of these phases, active hormones are working to:
- improve our memory,
- regulate mood fluctuations,
- boost our immune systems,
- improve brain power,
- develop emotional strength,
- aid wound recovery rate and
- thanks to collagen stimulating hormones which are active while even as we sleep, keep us looking younger!
If your sleep is fragmented or broken often, it's worth being proactive to fix this. Sleep supplements are powerful, natural ways to encourage the production of the sleepy hormones and have no long term effects, and are non addictive.