Deep sleep is one of the body’s most essential rejuvenation phases, supporting physical growth, memory consolidation and production of hormones that regulate stress, appetite, blood glucose levels and energy production.
Lack of adequate deep sleep is associated with reduced memory and learning capabilities, an increased risk for diabetes and obesity, reduced physical energy and weakened immunity.
1. You’ll feel groggy
Deep sleep is the slow-wave stage of non-REM sleep (NREM), during which body temperatures decrease, muscle activity and heart rate decrease, eye movements become reduced, and rapid bursts of activity from REM sleep are suppressed, making waking difficult and creating a mentally foggy state that may last up to an hour after awakening.
Healthy adults typically spend about 25% of their night sleeping in this phase. The duration can differ depending on an individual’s sleeping pattern and lifestyle; to maximize deep restful sleep it is best to stick to a consistent schedule, limit electronic devices use after midnight and heavy meals late at night, manage stress appropriately, drink less caffeine/alcohol beverages and exercise regularly.
Not getting enough deep sleep can have serious repercussions for memory and learning problems, diabetes and obesity, and a weakened immune system. Lack of restful REM sleep also raises cortisol levels – your primary stress hormone – which increases stress. Furthermore, inadequate restfulness has the ability to impact emotions by leaving you feeling irritable, stressed out, anxious or moody.
2. You’ll be more likely to get sick
Deep sleep (stage 3 of non-rapid eye movement sleep) is essential to restorative rest and overall health, as this phase sees heart rate and blood pressure reach their lowest points while memories are created and stored for long-term storage, feel-good chemicals like serotonin are released by your brain, and senses are stimulated.
An ideal night of rest includes cycles of both REM and non-REM sleep. Most adults require between 7-9 hours of uninterrupted REM- and non-REM sleep each night in order to function optimally, helping prevent stress, memory and learning problems, an increased risk of diabetes or obesity, reduced physical energy and weakened immunity systems.
Lack of adequate restful sleep may increase cortisol levels in your body – a stress hormone. Over time, this may contribute to depression and anxiety as well as increasing risk factors like rheumatoid arthritis or multiple sclerosis. The good news is that sleep disturbances can be resolved with improved sleeping routines and regular physical activity – the more you do to enhance your rest, the better off you’ll feel throughout the day!
3. You’ll be more susceptible to depression
Recharging with restorative sleep helps your brain repair and renew itself during restorative stages. Without enough restful slumber, hormone levels may shift out of sync, leading to trouble remembering what was said and thinking clearly.
People who sleep fewer than the recommended 7-8 hours each night don’t spend enough time in slow wave sleep (stages three and four). Deeper sleeping means your brain waves become delta waves that cannot be easily aroused – this restorative phase where tissues, muscles, bones, and immune function all heal themselves.
When your brain doesn’t get enough restful restful sleep, emotions become difficult to process and regulate; researchers have noted that insomnia makes people more sensitive to negative emotional information that would normally pass off easily when well rested; this may explain why teenage insomnia has been linked with depression and suicidal behavior in some teens.
For optimal deep restful sleep, aim to adhere to a regular sleep-wake schedule and avoid caffeine and alcohol prior to bedtime, taking naps as necessary and creating a soothing bedroom environment and evening routine.
4. You’ll be more prone to accidents
Most car crashes are the result of driver drowsiness, with those sleeping fewer than seven hours in any 24-hour period being at highest risk. According to research published in SLEEP journal, those missing 2-3 hours of sleep have four times greater odds of being responsible for an accident compared with those sleeping seven or more hours per night – this risk being comparable with driving with blood alcohol concentration levels exceeding legal limits.
Drowsiness can lead to costly errors in many workplaces, posing serious threats that have life-altering repercussions. Pilots, truck drivers, shift workers and medical residents are especially at risk from falling asleep on the job; pilots in particular face an increased risk. Chernobyl nuclear plant disaster was directly attributed to human error from lack of sleep while an identical mistake caused a fire at Boston warehouse in 1986.
Socioeconomically disadvantaged individuals are at greater risk for sleep problems due to stress and anxiety, with poor quality sleep being linked with chronic health conditions like heart disease and dementia.
5. You’ll be more prone to injuries
Though scientists are still discovering exactly what sleep does for us, its many effects on health are clear. From immune function to memory formation and beyond, sufficient restorative sleep plays an essential role in overall wellness and without it many of us would suffer serious consequences.
Sleep experts consider deep sleep to be one of the cornerstones of restful nights; otherwise known as slow wave sleep or non-rapid eye movement (NREM) stage 2. This stage accounts for most of an average sleeping cycle and serves an important purpose.
At nighttime, your body releases growth hormones to aid muscle repair and facilitate growth, with prolactin from your pituitary gland acting to regulate inflammation. When you lack deep sleep it can take longer for injuries to heal as well as put you at greater risk of further ones in future; lacking it could even cause microsleeps while driving or engaging in activities requiring full concentration such as using tools. If this type of restlessness continues over an extended period, injuries could worsen and microsleeps occur – potentially dangerous situations if microsleeps occur while driving or engaging in other activities that require full concentration.
