Sleep hygiene

• TYPE OF PSYCHOLOGY: Behavioral medicine; Biological bases of human behavior; Developmental; Family; Health; Social

Sleep Hygiene is the phrase coined for the structured set of guidelines created by sleep researchers and clinical sleep physicians to improve sleep in those with insomnia or difficulty initiating or maintaining sleep. The instructions are meant to be easy to follow by the average person, in their own home. Although neither a necessary nor sufficient component of cognitive-behavioral therapy for insomnia, clinicians and researchers agree that healthy sleep hygiene can be a helpful first step in improving difficulties with sleep.

Introduction

Although the origin of the term "sleep hygiene" and the original recommendations are still debated, sleep researchers have agreed upon a uniform set of suggestions to provide individuals with easy-to-follow strategies that can improve both sleep quality and quantity. These guidelines are typically included as an essential component of cognitive-behavioral therapy for insomnia, which is an intervention that has been shown to improve sleep in 70 percent of people. These guidelines can vary from clinician to clinician, and can include anywhere from four to twenty points. Here, we discuss eleven principles that have been established and supported by the most current research.

Keep a regular schedule

Our circadian rhythms are established and maintained through an interaction of functions, the most important of which are light and activity. In order to maintain a stable rhythm which facilitates falling asleep quickly and the ability to stay asleep throughout the night, one should maintain a regular activity schedule. This includes having consistent bed and wake times, eating meals at similar times each day, and engaging in regular activities.

It is important to also keep weekend bed and wake times as similar as possible to weeknight bed and wake times. Having drastically different bed and wake times on weekends can contribute to social jet lag, which is the discrepancy between our social and biological clocks. Social jet lag occurs when people go to bed and wake up much later on weekends than weeknights, and experience fatigue on Mondays when waking up at an earlier time is required. Social jet lag has been shown to be associated with increases in depression, obesity, and impulsivity. However, a 2024 study indicated that catching up on sleep on weekends can, in fact, benefit people who become sleep-deprived during the week, including lowering their risk of heart disease, stroke, and other illnesses.

Avoid napping during the day

Research has shown that our need for sleep, or sleep drive, increases throughout the day, resulting in sleepiness and fatigue at night which promotes sleep. Napping during the day reduces this sleep drive, which can result in increased alertness at bedtime, making it more difficult to fall asleep, or stay asleep throughout the night.

If napping is necessary due to medical conditions or otherwise, the following guidelines may help to keep naps from disturbing your sleep. Naps should be kept under thirty minutes, and occur before noon. Also, if napping occurs regularly, try keeping them scheduled at the same time each day. According to the National Sleep Foundation, these short naps, or power naps, can be beneficial.

Exercise during the day, but not too close to bedtime

Like many bodily functions, core temperature is regulated by one's circadian rhythms. At night, the body prepares for sleep by decreasing body temperature progressively to its natural low at around 4 AM. Because of this, anything that increases body temperature too close to bedtime, including exercise and hot showers, could interfere with this natural process and disturb sleep.

Moderate to vigorous exercise five to six hours before bedtime, however, has been associated with higher sleep quality, which may be due to increasing fatigue following exercise.

Avoid heavy meals and drinking liquids before bed

Eating, like exercise, also stimulates the body, but eating does so by activating the digestive system. Eating too close to bedtime, two to three hours before bed, may result in prolonging the amount of time it takes to fall asleep, or disturbing sleep quality since the digestive system is still quite active. Additionally, research has also shown that sleeping too soon following eating may result in acid reflux disease or heartburn, which can subsequently affect sleep. For those who tend to get hungry close to bedtime, having a small snack before bed may prevent nighttime hunger.

In addition to eating too close to bedtime, drinking copious amounts of liquids before bed may disrupt sleep by resulting in awakenings to use the restroom.

Avoid alcohol before sleep

Research has shown that the metabolism of alcohol within the body at night may also impair sleep. While drinking alcohol close to bedtime may result in mild sedative effects, it also tends to lead to disrupted sleep in the second half of the night.

Avoid smoking before sleep

An active component in tobacco is nicotine, a stimulant drug. Any stimulants ingested too close to bedtime can disrupt both falling and staying asleep. It is important to discontinue use of any tobacco products several hours before bedtime and not use tobacco in the middle of the night.

Limit caffeine intake

The neurotransmitter Adenosine is of great importance to the sleep system. It has a generally inhibitory effect on the central nervous system, decreasing neuronal activity, and signaling the brain and body to initiate sleep. Caffeine, being an adenosine-receptor antagonist, prevents adenosine from binding to the receptor and thus increases CNS-activity and alertness. The average half-life of caffeine is five to six hours, but can vary widely by individual and is also affected by many types of medications. Some types of oral contraceptives, for example, may double the half-life of caffeine, allowing it to stay in the body for upwards of twelve hours. In order to avoid disrupted sleep due to caffeine use, caffeine should generally be avoided, or only ingested several hours before bedtime. Be aware that many products other than coffee contain caffeine, such as black or green tea, certain sodas, and chocolate.

Wind down 1 hour before bedtime

Like our bodies after exercise, our minds need time to relax after a busy day before being able to initiate sleep. Working or remaining actively engaged in responsibilities until bedtime can result in longer periods of time to fall asleep.

Although many people feel that watching television or using their smartphone is the optimal way to wind down before bed, research has demonstrated that bright light, and light waves from the blue spectrum of light specifically, commonly used in electronic devices like cell phones and television, can suppress melatonin, the hormone responsible for signaling sleep. This melatonin suppression results in a longer period of time taken to fall asleep. To wind down effectively, light levels should be kept low for the hour before bedtime, and screens should be switched off. If one uses a cell phone or other device several hours before bedtime, blue light blocking features can be used. Reading quietly before bed can provide the relaxation and calm that can facilitate sleep.

Optimize the bedroom for sleep

As mentioned, light typically disrupts sleep, so it is important that a sleeping environment be dark, or have the ability to be dark when necessary. Room-darkening shades or curtains can provide darkness at night, but can also be opened during the day to provide natural light.

In addition to having a dark environment, proper temperature also facilitates undisturbed sleep. The circadian system works to lower body temperature during the first half of the night. Any event that causes an increase in body temperature, therefore, can disrupt sleep. Room temperatures at approximately 65 degrees Fahrenheit are adequately cool to prevent temperature-related awakenings. Utilizing a programmable thermostat can allow the bedroom environment to be kept cool in the middle of the night, but warm in the evenings and mornings.

Extraneous sounds can also cause middle-of-the-night awakenings. To reduce the likelihood of sleep disturbance due to noise, white noise generators such as fans, humidifiers, or sound machines can be used.

In addition to light, temperature, and sound, it is vitally important that one's sleep environment is physically comfortable. Investing in a comfortable bed, pillows, and sheets is recommended.

Avoid clock-watching

Many people sleep with a clock or clock-like device near their bed. While this may serve a necessary function, like having an alarm that signals the appropriate wake time, it can also facilitate clock-watching behavior. Time or clock monitoring behavior has been shown to increase anxiety and disrupt sleep, especially in those with insomnia. If having a clock near the bed is necessary, consider turning the clock-side to not face the bed. In this way, the alarm can still function, but it won't allow for clock-watching in the middle of the night.

Use bright light to increase alertness in the morning

Just like bright or blue light from a TV or smartphone in the evening suppresses melatonin making it more difficult to fall asleep, bright light in the morning can provide a much-needed boost in alertness by suppressing melatonin when you are supposed to be awake. Upon awakening, open blinds or curtains to let in natural light, and go for a brief walk outside in the daylight.

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