The importance of sleep
Sleep is an essential bodily function that affects all organ systems and is necessary for life. It assists in several important processes in the body including physical recovery and repair, as well as improving learning, memory, mood and immune function. It is now known that sleep supports brain development, cardiac function and healthy metabolism as well as many other essential bodily functions.
The close relationship between sleep and human health means that regular poor sleep contributes to multiple health issues including cardiovascular disease, hypertension, type 2 diabetes, obesity, poor mental health and shortened life expectancy. Three large cross-sectional epidemiological studies showed that sleeping less than five hours per night increased the risk of dying by 15 percent.
During sleep, important biochemical reactions occur within the body, including the secretion of hormones that help to control energy metabolism, appetite, glucose processing and regulation of stress hormone production. Poor sleep is associated with increased production of the stress hormone known as cortisol, as well as increases in insulin release following meals which promotes fat storage and contributes to diseases like diabetes and obesity.
Sleep disturbance also has important short and long term effects on mental health, mood, stress and anxiety. A single sleepless night can result in irritability and low mood. Chronic (meaning long-term) sleep disturbance is associated with higher rates of anxiety, depression and mental distress. Higher levels of mental distress can also contribute to poor sleep quality and duration, resulting in a vicious cycle of sleep and mood confounding each other and contributing to further mental distress.
What is insomnia and how common is it?
Insomnia is in fact a diagnosable medical disorder with defined diagnostic criteria which include self-reported poor sleep quality, or inadequate sleep despite adequate opportunity to get sleep, and is accompanied by impairment of daytime function. It is estimated that 11.3% of the general population meet the diagnostic criteria for insomnia, making this one of the most common disorders affecting the adult population. It tends to affect young and middle-aged adults rather than the elderly. Many people report sleep disturbance and may not necessarily meet the diagnostic criteria for insomnia. It is estimated that around one third of adults (30 - 36%) have symptoms of insomnia such as poor sleep quality or non-restorative sleep.
Anxiety and stress and its relationship to sleep
Sleep disturbance, stress and anxiety commonly occur together. Poor sleep can be an important cause of mental health issues and higher rates of anxiety. Similarly anxiety can be an important cause of sleep disturbance. Night time anxiety is very common, and might occur for a variety of reasons. Many people who are affected by anxiety or stress may lie awake at night ruminating on events of the day before, or remain apprehensive about their anticipation of a poor night's sleep or being unrefreshed the following day. The perceived distress that accompanies an inability to fall asleep can result in an increased fight or flight response that only serves to exacerbate the problem.
What is anxiety and stress?
Stress is a normal human reaction that is generally only harmful if present in excessive amounts. Low to moderate amounts of stress can help to improve efficiency, cognition and concentration that can be helpful in everyday life. However, excessive or chronic stress can result in a suite of chronic health issues. Stress is a consequence of normal life and can be affected by a number of factors which may be within or outside of our control.
Anxiety is a state of stress with a wide spectrum of severity that may affect individuals very differently. Some people may have low levels of underlying anxiety which doesn’t necessarily affect their ability to function, and in some cases it may even be beneficial and conducive to daily functioning. In fact, many people achieve great success in life as a direct result of underlying anxiety and perfectionistic personality traits. Anxiety and stress therefore is a symptom, the severity of which will dictate whether it is beneficial or contributing to psychological or physical dysfunction.
The following 7 symptoms may have the potential to cause significant distress and may impair social and occupational function and satisfaction. If you feel like you might have any of these symptoms, it's important to talk to a General Practitioner or qualified Psychologist:
- Restlessness or feeling keyed up or on edge
- Being easily fatigued
- Difficulty concentrating or mind going blank
- Muscle tension
- Sleep disturbance - (including difficulty falling or staying asleep or restlessness)
- Panic-like symptoms (including difficulty breathing, trembling or sweating)
Important medical causes of sleep disturbance
While anxiety and stress remain important causes of sleep disturbance, it's also important to be aware that there are a number of other important medical causes for sleep-related problems. For this reason, it’s important to consult your doctor if you are suffering from sleep problems as some of these issues may need to be addressed.
One of the most common causes of impaired sleep is Obstructive Sleep Apnoea (OSA). It is estimated that OSA affects up to 38% of the general population and may be responsible for a significant number of roadside deaths due to resultant fatigue from the condition itself. Common symptoms include snoring, recurrent cessation of breathing during sleep (apnoea), as well as daytime fatigue and headaches. OSA can affect people of all ages, and is frequently linked to higher BMI and obesity. Rising rates of obesity in western societies are correlated with an increasing incidence of OSA making this a growing public health issue. It is important to note that OSA can be easily diagnosed with a sleep study and treated effectively by addressing problems with body weight and devices like mandibular advancement splints and CPAP machines.
There are many other important medical causes of sleep disturbance including thyroid disturbance, heart disease, respiratory disease, chronic pain, alcohol use, reflux and indigestion. For this reason, a comprehensive review with your doctor is important to identify the underlying source of sleep disturbance.
Lifestyle factors that commonly affect sleep
In our conventional 24/7 society, there are innumerable social, societal and environmental factors that may adversely affect sleep. The digital age for example has resulted in round-the-clock use of mobile phones, the internet and television which continue to encroach upon valuable sleep opportunity. This not only results on less available time to attempt to sleep but can also interrupt our ability to fall asleep (resulting in increased ‘sleep latency’) as well as our ability to achieve quality restorative sleep. The advent of a 24/7 society has resulted in an increased number of people performing ‘shift work’, which causes significant disruption to circadian rhythm and associated sleep disorders.
How much screen time is too much screen time? Studies that have tested the effect of bright lights from laptop screens, phones and iPads on sleep tend to suggest that exposure to screen light for more than 1.5 hours in the evening results in reduction in both melatonin release and perceived sleepiness. The stimulating effect of increased screen time also results in increased alertness and cognition which can further exacerbate trouble falling asleep. Studies have also shown that repeated screen exposure over 5 days can delay the body clock by 1.5 hours resulting in people wanting to go to bed later and sleep in longer. This may contribute to problems like Delayed Sleep Phase Syndrome (DSPS).
The time at which we expose ourselves to digital screens is also important. Increased screen time use in the hour prior to bedtime results in reduced sleep satisfaction and increased daytime fatigue.
If you find it hard to avoid screen time in the lead up to bedtime, there are a few things you can do to help reduce detrimental effects of screen time on sleep:
- Dim the screen on your phone or laptop
- Download a computer software program on your laptop that can reduce blue light exposure (e.g. ‘f.lux’)
- Invert the screen colour on your eReader (white text on black background)
Things you can do to reduce stress
An important cause of stress is disruption in life balance. The acronym PRAISES is a useful tool to improve life balance and reduce stress. PRAISES stands for:
- Physical health and self-care. Addressing physical health issues can help reduce stress. For example, treating chronic pain and optimising symptom control of chronic conditions can have a remarkably positive impact on personal satisfaction and perceived level of distress. It’s also important to increase healthy habits like physical activity and healthy nutritional intake, and reduce unhealthy habits like smoking, alcohol and recreational drug use.
- Recreational. Increased engagement in fun or relaxing recreational activities
- Artistic. Engaging in creative pursuits or appreciating creative pursuits of others (e.g. listening to music, watching a live performance, or learning to play an instrument).
- Intellectual. Actively seeking to learn and participate in learning new activities, tasks or skills.
- Spiritual. Improving spiritual connection beyond self and family can have an important impact on perceived levels of stress (e.g. religious or community pursuits, kindness and altruism toward others).
- Employment. Pursuing financial or employment opportunities and achieving career-related goals. However, it’s important that excessive work can disrupt work-life balance and contribute to higher levels of stress. Work-life balance is key here.
- Social. Increasing time spent with significant others such as close friends and family.
- Music therapy
- Relaxation techniques
- Counselling and psychotherapy
Things you can do to improve sleep
In addition to efforts to reduce stress, there are a number of important factors to consider that can affect sleep. Sleep hygiene refers to improving adherence to activities that promote healthy restorative sleep.
To improve your chances of falling asleep and achieving a healthy amount of rest, it is important to consider the following:
- Get up at the same time each day, regardless of the amount of sleep you've had. This will help you to attain a regular sleep-wake cycle, and improve your chances of falling asleep the following night.
- Go to bed only when you’re feeling sleepy
- Get out of bed if you’re unable to fall asleep within 20 minutes. If you do this, go to a quiet place and engage in a non-stimulating activity like reading a book. Go back to bed when you feel sleepy.
- Reserve the bedroom only for sleep and sex. Don’t watch TV, read, use your laptop or work in your bedroom.
- Do not nap during the day
- Don’t drink coffee in the afternoon and evening
- Avoid cigarettes and alcohol at night, and other substances and stimulants that disturb sleep.
- Regular exercise is helpful, but exercise late at night is detrimental.
- Make the bedroom as dark as possible.
- Ensure your bed is comfortable and consider temperature control.
Sleep, stress and anxiety commonly occur together and there are many things you can do to reduce levels of stress and promote quality sleep. If you’ve tried all the above and still can’t sleep, it’s essential that you see your doctor for specific health advice. It’s important to exclude common medical causes for sleep disturbance and to consider psychological counselling if you’re suffering from excessive anxiety. There is also some evidence for the use of some health supplements to assist with stress and sleep issues, however they tend to vary in quality, dose and effectiveness.
At IMUNI, we are currently reviewing the evidence for the use of health supplements to promote sleep and reduce the stress response. You can subscribe by email at imunihealth.com to stay up to date with the latest evidence.
- Duns G. 2019. Sleep and Health. Australian Journal of General Practice. Available from: https://www1.racgp.org.au/ajgp/2019/april/sleep-and-health
- Good sleep = Good Health. Government of South Australia (SA Health). Available from: https://www.sahealth.sa.gov.au/wps/wcm/connect/public+content/sa+health+internet/healthy+living/heal...
- Sleep and Disease Risk. Harvard Health. Available from: http://healthysleep.med.harvard.edu/healthy/matters/consequences/sleep-and-disease-risk
- Grima et al. 2019. Insomnia theory and assessment. Australian Journal of General Practice. Available from: https://www1.racgp.org.au/ajgp/2019/april/insomnia-theory-and-assessment
- Ferrie et al. 2011. Sleep epidemiology - a rapidly growing field. International Journal of Epidemiology. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3655374/
- Technology and Sleep. 2016. Sleep Health Foundation. Available from: https://www.sleephealthfoundation.org.au/technology-sleep.html
- Sleep is an essential bodily function that affects all organ systems and is necessary for life.
- Sleeping less than five hours per night increased the risk of dying by 15 percent.
- One in three adults has symptoms of insomnia.
- Sleep apnoea affects up to 38% of the population