The Importance of Sleep (2024)

Sleep is important due to the impact it has on your overall health. Appropriate sleep is needed for mental focus and memory, managing stress, maintaining proper body weight, boosting the immune system, and a host of other wellness needs. Some studies suggest sleep can help to prevent illness, such as diabetes or obesity.

Adults aged 18 to 60 years should get at least seven hours of sleep each night in order to achieve the benefits of sleep. If not, you run the risk of becoming sleep-deprived.

This article explains the role of sleep in overall health and offers tips on how to improve your sleep. Research on sleep and sleep cycles has elevated awareness about sleep hygiene (healthy sleep habits) and the quality of sleep.

Sleep Is Restorative

When you sleep, you allow your body to repair and rebuild. During this time, the body is able to clear debris from the lymphatic system, which boosts the immune system.

While you sleep, there are many important processes that happen, including:

• Muscle repair
• Protein synthesis
• Tissue growth
• Hormone release

Sleep Reduces Stress

Sleep is a powerful stress reliever. It improves concentration, regulates mood, and sharpens judgment and decision-making. A lack of sleep not only reduces mental clarity but the ability to cope with stressful situations.

This is due, in part, to changes in cortisol levels. Typically, your cortisol levels fall in the evening hours, as one element of the body’s natural preparation for sleep. When sleep is lost, cortisol levels remain high and interfere with the release of melatonin, a hormone that is essential for the regulation of sleep-wake cycles.

Some studies suggest these changes could even be used to evaluate depression in people with bipolar disorder. Other studies demonstrate a link between sleep, chronic stress, and depression with an eye on heart rate changes.

Sleep Improves Your Memory

The link between sleep and memory processing is well established. Sleep serves as an opportunity for the mind to process all the stimuli taken in while awake. It triggers changes in the brain that strengthen neural connections helping us to form memories.

Sleep quality is important when learning new information and using memory. Numerous research studies find that electrophysiological, neurochemical, and genetic mechanisms that take place during the slow-wave sleep stage of sleep are key.

Sleep Helps You Maintain a Healthy Body Weight

When you are sleep deprived, your body alters the hormones that regulate hunger and appetite. These hormones include:

• Leptin: This hormone suppresses appetite and encourages the body to expend energy.
• Ghrelin: This hormone triggers feelings of hunger.

Both of these hormones are thrown off when you are short on sleep—leptin goes down and ghrelin goes up. Obstructive sleep apnea, a serious sleep disorder, is linked with obesity as well.

Sleep May Prevent Illnesses

Sleep deprivation can have very detrimental health impacts and has been linked to chronic diseases such as diabetes and heart disease. Here are some of the health conditions in which it may play a role.

Respiratory Illness and Infection

Lack of sleep makes you more vulnerable to respiratory illness and infection. A study of more than 600,000 people found that insomnia was a contributing cause when catching a cold or the flu, as well as a factor in how severe the infection became.

Heart Disease

Obstructive sleep apnea, a common sleep disturbance, is linked with a number of cardiovascular (heart and blood vessel) diseases. For example, 40% to 60% of people experiencing symptomatic heart failure also are diagnosed with sleep-disordered breathing.

Other heart conditions linked with sleep apnea include:

• Coronary artery disease
• Stroke
• Pulmonary hypertension
• High blood pressure
• Heart arrhythmias
  

Cancer

There's no direct evidence to suggest that sleep quantity or quality affects the risk of cancer, although studies have looked at the role of sleep in developing breast cancer, lung cancer, and more.

For example, research on lung cancer suggests a relationship between lack of sleep and adenocarcinoma risk, but more research on sleep traits (how long you sleep, whether you take naps) is needed.

Studies also are exploring the role of sleep in those already diagnosed with cancer, especially because difficulty sleeping affects up to 95% of people receiving cancer treatment and care. Sleep deprivation may affect the body's ability to fight cancer and lead to a poor prognosis, which was the conclusion of researchers focused on liver cancer.

Diabetes

A number of studies have shown that sleep deprivation leads to reduced glucose tolerance and impaired insulin sensitivity in humans. Additional studies suggest the risk of type 2 diabetes rises due to inadequate sleep, with seven or eight hours considered the optimal amount.

Researchers also think the timing of sleep may have impacts, too. Disruptions in circadian rhythm, with many people working at night or otherwise "living against the clock" of natural sleep cycles, also have impacts. Sleep disruption appears to affect metabolism and related diseases.

Neurodegenerative Disease

Sleep plays a key role in how your body produces cerebrospinal fluid (CSF), what it's composed of, and how the CSF is distributed in your brain and spinal cord. A number of studies have looked at how components in CSF, like amyloid-beta levels, might be linked to Alzheimer's disease and other neurodegenerative disorders.

The research results are mixed, but there is evidence to suggest that sleep patterns affect levels of amyloid-beta, orexin, tau proteins, interleukin 8 (IL-8), and other components. This may influence the development of Lewy body dementia, Parkinson's, or Alzheimer's disease, or it may contribute to sleep disruptions that are common in people living with these disorders.

Researchers also are investigating the role of CSF, sleep, and the early development of autism.

Sleep Is Important for Your Mental Health

Evidence suggests lack of sleep contributes to the formation of new mental health problems and to the maintenance of existing ones, but the magnitude of its effect is difficult to estimate and may be different across mental health conditions.

Sleep problems are very common in those with mental illness. In fact, disrupted sleep is commonly seen as both a symptom and consequence of mental health disorders, although sleep deprivation is rarely treated as the cause of mental health conditions.

The most common sleep problem associated with poor mental health is insomnia, with symptoms of:

• Not feeling well-rested after a night's sleep
• Daytime tiredness or sleepiness
• Irritability, depression, or anxiety
• Difficulty paying attention, focusing on tasks, or remembering
• Increased errors or accidents
• Ongoing worries about sleep

You may experience insomnia for a number of reasons, but the most common culprits are:

• Stress
• Work schedule
• Poor sleep habits
• Excessive alcohol or caffeine use at night
• Habitual nighttime screen use

How to Improve Your Sleep

Small changes to your nighttime routine can result in a huge health benefit:

• Establish a realistic bedtime and stick to it every night, even on the weekends.
• Maintain comfortable temperature settings and low light levels in your bedroom.
• Consider a “screen ban” on televisions, computers and tablets, cell phones, and other electronic devices in your bedroom.
• Abstain from caffeine, alcohol, and large meals in the hours leading up to bedtime.
• Refrain from using tobacco at any time of day or night.
• Exercise during the day; this can help you wind down in the evening and prepare for sleep.

Summary

Sleep is vital to maintaining health, and most adults need seven or more hours each day. There is increasing evidence that adequate, high-quality sleep can help prevent illnesses like respiratory infection as well as limit the risk of diabetes, heart disease, and other serious conditions.

Memory, mood, and mental health also are affected by sleep deprivation and other sleep disorders.

There are lifestyle steps you can take to improve sleep. Talk to your healthcare provider if you have concerns or questions about how sleep patterns are affecting your health.