By Lindsay Nixon, RN, BSN – Guest Contributor
One of many health messages over the past 5 years is the importance of sleep. Like many commands of health, it is easy to make these claims but more difficult to put them into practice. While most are busy balancing work, family, and life, sleep plays a silent role in how we function while we are awake.
Biologically, we all have a sleep cycle called a circadian rhythm. This rhythm repeats every 24 hours and occurs when your body releases different hormones in response to being exposed to light. Cortisol is released in the morning, and melatonin is released in the evening. Together, the hormones help your body stay awake or fall asleep, depending on the time of day.
Sleep is categorized as non-rapid eye movement (NREM) and rapid eye movement (REM). NREM sleep includes the first three stages of the sleep cycle, while REM is the last and final stage. After you finish the cycle, it starts over from the beginning.
During the first two stages of NREM sleep, your body is relaxing, and you drift into deeper states of sleep. In the third stage of NREM sleep, slow-wave sleep (SWS), the cells in your brain rest as electrical activity slows. A 2019 study found that during SWS, the fluid that your brain and spinal cord use for lubrication washes away the natural wastes your body creates each day.
The NREM sleep stages last approximately 90 minutes, after which you go into the REM stage. During the REM stage, your eyes move back and forth quickly – giving this stage its name (Rapid Eye Movement). This stage is also known as the “dream state”, as you experience your most vivid dreams. During REM, the brain does the important job of processing information and consolidating memories by moving them from your short-term to long-term memory. This stage lasts about 30 minutes during your first cycle, with the length of this stage increasing throughout the night as you progress through multiple cycles.
The third stage of NREM and REM are the most critical phases of the sleep cycle, making it very important to have uninterrupted sleep. The amount of sleep your body needs decreases as you age, but not by as much as some may think. A school-age child should get between 9 and 11 hours of sleep, while a teenager should get 8 to 10 hours. Adults are recommended to get 7 to 9 hours of sleep. It is recommended that older adults (age 65 and above) should get at least 7-8 hours of sleep.
To get a better understanding of your sleep cycle, there are apps that can track your sleep. Sleep Score, ranked the best sleep app of 2021 by the New York Times, uses your smartphone microphone and speaker to track your sleep cycles. Smartwatches and fitness trackers often offer sleep tracking capabilities, monitoring the length of time spent in each stage, sleep schedule trends, and heart rate and breathing information while asleep.
If you have trouble sleeping, it is helpful to watch your exposure to light to avoid the unintentional release of cortisol. Experts suggest avoiding large meals and stimulants such as caffeine before trying to fall asleep. It is also helpful to maintain a predictable sleep schedule and wake up and go to bed at the same time each day, even on the weekends. If you feel that you need a mid-day nap, try not to sleep for longer than 20 or 30 minutes, as this may make it more difficult to fall asleep later.
If you work the second or third shift, a good sleep/wake cycle may seem like an unattainable goal. Avoiding light before trying to fall asleep, avoiding caffeine in the hours leading up to sleep, and abstaining from tobacco and alcohol are all good practices. Using dark curtains or a sleep mask can help you stay asleep while the sun is up.
The light emitted from screens has also become a problem for people who have difficulty sleeping. TVs, cell phones, and tablets give off a blue light that interrupts naturally occurring hormones that help you fall asleep.
Poor sleep hygiene can cause problems such as mood swings, forgetfulness, difficulty concentrating, and may increase the risk of health problems such as obesity, diabetes, high blood pressure, and heart disease. If you struggle to get enough sleep, it’s best to talk to your doctor. Suggestions ranging from meditation, dietary changes, and medication are all possibilities that your physician can review with you.