In today’s on-the-go society, sleep is often viewed as expendable or something people desperately want but cannot seem to make time for. When sleep is achieved, it is often too little to be effective. The reason for this, in part, is that sleep itself is poorly understood by society and science. Many people underestimate the effect sleep has on our overall physical and mental health. It may be intuitive that sleep is required for your body to repair and regenerate. However, it is less obvious that sleep improves immune function or has a major impact on mood and vulnerability to depression. Sleep is an essential element for proper upkeep of our entire biology. About 1/3 of our lives are spent sleeping and sleep plays a critical role in how happy, energetic and successful the other two-thirds of our lives can be.
Four stages of healthy sleep:
Light sleep
- Stage 1 - it's easy to wake you up.
- Stage 2 - body temperature drops - preparing for deep sleep.
Deep sleep (Restorative Sleep)
- Stage 3 - a transitional period between light and very deep sleep.
- Stage 4 - the deepest sleep. Growth hormone is released. Blood supply to muscles increases, tissue growth and repair occurs, energy systems are restored.
Rapid Eye Movement (dreaming in progress)
- REM dreaming occurs only in deep sleep
In stage 1 sleep you are in the process of falling asleep but have not quite allowed yourself to begin sleeping-. In stage 2 sleep, you start to tune out everything around you. You maintain a regular heart rate and breathing pattern, but your body temperature is dropping.
Once you have entered stage 3 you have entered the deep sleep and restorative sleep phases. These phases are also where REM sleep occurs. REM is when dreaming occurs, and the body becomes immobile because muscles are turned off. Your blood pressure drops and breathing becomes slower. REM sleep occurs about 25% of the time you are in a deep sleep. After sleeping for approximately ninety minutes, the body enters the first round of REM sleep. These stages will repeat every ninety minutes.
During stages 3 and 4 of sleep is where healing is accelerated including muscular development and memory modeling. Growth hormone is released in deep sleep which activates tissue growth and repair while it restoring energy reserves for the next day.
Finally, during the last several cycles of sleep, the body initiates ramp-up procedures. An increase in the hormone cortisol helps prime alertness for the following day. Appetite modulating hormones ghrelin and leptin are regulated throughout the night; both are crucial for control of hunger and food related satisfaction while awake.
Sleep Disruption and Fragmentation
Sometimes poor sleep is related to disorders such as sleep apnea or insomnia. A sleep study may be necessary to diagnose the issue and provide aids to help rectify sleep problems. Sleep studies are conducted in a “sleep lab.” The lab consists of comfortable rooms set up as bedrooms. The patient is then hooked up to diagnostic devices, such as a heart monitor, oxygen monitor and EKG. The subject is asked to go about their bedtime routine as close as possible and then is medically and visually monitored as he sleeps. The monitoring helps accurately diagnose a sleep disorder.
Two of the most common sleep disorders are sleep apnea and insomnia. With sleep apnea, the subject stops breathing throughout the night. As a result, deep sleep is interrupted or prohibited, causing the subject to feel exhausted even after “sleeping” for eight hours. Sleep apnea can be treated surgically or with a breathing machine to help support the breathing process throughout the night. While newer machines are very quiet and more comfortable than older models they require some getting used to. Once the patient adjusts to using the machine the quality of sleep will improve thereby substantially improving the patient’s overall quality of life. It is also important to note that sleep apnea can be directly related to obesity. If the subject begins to sleep better, he may have more energy to exercise and produce better levels of ghrelin and leptin to improve appetite control and aid in weight loss. Weight loss frequently helps resolve sleep apnea.
Insomnia is the inability to fall asleep or stay asleep. The patient may become restless, and while tired, may be unable to “turn off his brain” to fall asleep. There are many causes for insomnia including biological causes, alcohol or substance use, some medications (cold and allergy drugs) or general unhealthy sleep habits. As we age, we tend to get less deep, restorative sleep. Aging is also linked to shorter time spans of sleep, although you still need as much sleep as when you were younger.
Sleep Deprivation
No matter the issues, if you are not receiving sufficient sleep each night you risk serious physical and mental health consequences as you further sink into chronic sleep deprivation. Issues such as weight gain, hypertension, poor immunity, muscle and body aches, higher likelihood of injury, depression, memory impairment, anxiety disorders, and an increased risk of Alzheimer’s dementia can result from chronic sleep deprivation. As a consequence, your quality of life drastically decreases, which makes you crave more sleep. At Baza Medical we understand this and refer our patients to highly skilled sleep specialists if poor sleep quality is suspected.
To be continued…
Sleep is a critical element for a robust, active life - especially if you place high value on fitness, athleticism, intellectual prowess and emotional equanimity. In another blog we will discuss strategies for better sleep and enhanced recovery as well as new research that is beginning to unravel the mystery of why we need sleep at all.
J. Michael Baza, MD
