STRESS AND SLEEP
STAGES OF SLEEP
Sleep, like oxygen, food, and water, is one of our few basic daily needs. Yet, many people who experience high levels of stress have problems with sleep disruption and getting poor sleep can also worsen stress. In order to reduce stress through healthier sleeping habits, it is important to understand some basic facts about sleep. Many people develop or worsen sleep difficulties because they do not have an accurate understanding of the sleep process! During a healthy night of sleep, we each experience two primary sleep phases: Non-Rapid Eye Movement (Non-REM) sleep and REM sleep.
Non-REM sleep occurs in three stages and accounts for 75-80% of our night’s sleep. Sleep stage1 of Non-REM sleep is the bridge between being awake and asleep and represents 5% of most people’s sleep cycle. Stage 2 is a deeper sleep that accounts for the most time out of all the stages of sleep, taking up somewhere between 40-55% of a night’s sleep. The third and final stage of Non-REM sleep is delta or slow wave sleep, accounting for 10-20% of sleep. This is the stage that helps our bodies feel refreshed and alert the following day.
REM sleep represents the final 20-25% of the sleep cycle and is the phase of sleep when most dreaming occurs. During REM sleep, we experience bursts of rapid eye movements. Heart and respiration rates become variable and more blood flows to the brain. Interestingly, this phase of sleep is relatively light and brainwave activity is very similar to that seen during wakefulness. However, during REM sleep, the body’s skeletal muscles are in a relative state of paralysis. This paralysis, in turn, prevents us from ‘acting out’ the dreams that occur during this phase of sleep.
A few important pieces of information to keep in mind about the sleep cycle:
We normally experience deeper Non-REM sleep during the first half of the night and REM sleep closer to when we wake up, which helps explains why we are more likely to awaken in the later portion of the night.
REM periods become more extended toward the morning rising time and is not uncommon for REM sleep to immediately precede the morning wake-up.
It is not uncommon for even good sleepers to be awakened briefly several times during the night. Such brief wake-ups are neither unusual nor cause for concern. Only when these awakenings are very frequent and extended do they indicate that a sleep problem is present.
THE BIOLOGY OF SLEEP
While all scientists agree that sleep is essential for daily functioning, they disagree about why. Some believe cells and tissues are healed during sleep, while others believe sleep helps regulate body temperature or metabolism. However, there is consensus around the circadian clock, biological clock based in the brain, which follows a s 24-hour sleep/wake cycle and determines when we are sleepy or awake. The circadian clock responds to external light to calibrate itself and determine if melatonin, a natural hormone that regulates sleep, should be released into the body. Normally, we release more melatonin in the evening and less during the day, making us sleepy at night and alert throughout the day. This helps explain why night shifts can feel challenging and the reason that light from cell phone screens can harm our sleep.
Although sleep needs vary from person to person, it is typical for the average amount of sleep we need each night to change throughout our development. When healthy adults are given unlimited opportunity to sleep, they sleep on average between 8 and 8.5 hours a night, while newborn babies sleep between 16 and 18 hours a day. If sleep needs are not met, a progressive sleep debt occurs. It does not appear that we are able to adapt to getting less sleep than our bodies require, and there is therefore, there’s little to stop a lack of sleep from impairing motor and cognitive function.
The biological consequences of sleep are numerous. Besides feeling lousy and tired, sleep disruptions can harm the natural fluctuations in blood sugar levels throughout the night. One study found that, when healthy young men slept only 4 hours a night for 6 nights in a row, their insulin and blood sugar levels mimicked those seen in people who were developing Type 2 diabetes. Another study found that women who slept less than 7 hours a night were more likely to develop Type 2 diabetes over time than those who slept between 7 and 8 hours a night. Sleep studies also suggest that healthy sleep, on the other hand, improves learning and memory
RECOMMENDATIONS FOR SLEEP DIFFICULTIES
Roughly one in six Americans experience chronic insomnia, and about 95% of Americans have experienced stress-induced brief insomnia at some point in their lives. Keep in mind that occasional bouts of insomnia are understandable and inevitable reactions to significant life events, such as losses like death or divorce. This stress-induced insomnia can be adaptive to allow people to think about stress triggers for longer and better cope with them. Fortunately, this type of insomnia, called short-term insomnia, typically persists for only a few days or weeks, and once the precipitating stress trigger fades or we have adjusted to it, life and sleep return to normal. Sometimes, however this transient insomnia can transform into chronic insomnia. Indeed, people’s concern over their lack of sleep is what often leads to the more chronic insomnia!
Other conditions, such as sleep apnea, can affect sleep as well. Sleep apnea occurs when a person’s breathing either stops or is interrupted while they are sleeping, which can prevent deep sleep and result in daytime sleepiness. Despite its disruptiveness, people with sleep apnea may not even know they have the condition and could misattribute the reason for their fatigue. For this reason, it’s always a good idea to seek out professional help if you’re struggling with sleep. Using substances are another barrier that can harm quality sleep. Caffeine, nicotine, alcohol, and certain medications like decongestants, steroids, heart and blood pressure medication, and pain relievers can also harm sleep for different reasons.
If you drink caffeine, a great first step to improve sleep is to try to reduce the amount of caffeine you drink to three cups a day and stop drinking caffeine once the late afternoon hits. Other tips include drinking less alcohol, doing more physical activities earlier in the day, having a light snack before bed, and keeping the bedroom quiet, dark, and at a temperature under 75 degrees.