The World Health Organization (WHO) and Centers for Disease Control and Prevention (CDC) are increasingly focusing on the burden of non-communicable diseases (NCDs), which are collectively responsible for approximately 74% of all premature deaths worldwide. Most of these premature deaths due to NCDs occur in low- and middle-income countries. The NCDs that are addressed include obesity, hypertension, diabetes, chronic lung diseases, heart disease, stroke, and cancers. Sleep disorders, which are perhaps more common, and can impact several of these conditions, are often under-recognised and ignored. This epidemic of NCDs has significant health consequences for individuals, and the risk factors include physical inactivity, unhealthy diets, substance use (tobacco and alcohol), and poor sleep.
Sleep is a fundamental and essential component of human health, influencing various physiological and psychological processes. While sleep requirements vary with age, the ideal sleep requirement for adults is 7 to 8 hours. With changing lifestyles, we are adapting to sleeping less, at the risk of affecting our physical and mental health. Strategies to improve sleep health, and recognise and treat sleep disturbances early will have far-reaching implications on health, productivity and the economy, and must be a global imperative.
There is a global disparity in data relating to sleep health and only a few countries (22% of WHO member countries) have collected and published population-level sleep duration data. While public health campaigns promoting smoking cessation, healthy eating, and physical exercise are common, it is disappointing that there is inadequate focus on sleep as a public health issue.
The prevalence of sleep deprivation
Globally, sleep deprivation affects a significant portion of the population in our modern society. Research and surveys on sleep habits around the world reveal alarming changes in sleep rhythm. In the United States, approximately one-third of adults report insufficient sleep, and in Australia, 20% of individuals regularly take medication to fall asleep, with 8% doing so every night. Studies from Europe also reveal similar prevalence rates of insomnia (23.5%). In a survey in the United Kingdom, 90% reported current sleep problems and two-thirds of them for more than six years. ‘Sleep Poverty’, described as reduced sleep quality due to poor living conditions and noise pollution, was noted in 30% of this group.
It is estimated that 61% of Indian adults sleep less than seven hours and the highest incidence is in the age group of 30 to 50 followed by those in the age group of 16 to 30. Interestingly, 64% of India’s urban population wakes up before 7 a.m., which is considered the highest in the world. It has also been observed that the world sleeps even less in the post-COVID era. During the pandemic and associated lockdown period, we observed that lack of sunlight exposure, changing lifestyles (predominantly working from home), fear of COVID, and uncertainty of the future led to altered sleep rhythms and sleep deprivation. It would not be an understatement to say that individuals in our modern society are ‘dying for a good night’s sleep’.
Health consequences of sleep deprivation
It is important to recognise that it is not just the quantity of sleep that matters, but also the quality. Sleeping at the right time, for the right duration, and experiencing the various stages of sleep in the right proportion make one feel refreshed. The circadian and diurnal rhythm of various hormones secreted in the body may be adversely affected by sleep deprivation and altered sleep rhythm. It must be emphasised that sleep health is not just about getting the right amount of sleep but encompasses regularity, satisfaction, and efficiency of sleep.
A good night’s sleep improves memories, ideas, concentration, and productivity. Those who have a sleep debt may be functioning at a fraction of their capabilities, often not recognising this. Sleep-deprived individuals may experience daytime fatigue and sleepiness, chronic headaches, irritability, poor attention span, impaired memory and cognitive deficits. Daytime fatigue and sleepiness increase the risk of daytime accidents and critical mistakes in the workplace as well as declining academic or professional performance. However, it has been observed that the perceived daytime subjective sleepiness in Indians is low (25%) depicting the denial of sleep deprivation and lack of awareness of the positive impact of good sleep on health and wellness. The impact of inadequate sleep extends beyond daytime fatigue. Chronic sleep deprivation is linked to numerous health problems, including cardiovascular, metabolic and mental health issues. Sleep problems often precede symptoms of burnout in individuals.
Sleep deprivation increases the risk of hypertension, heart attacks and strokes and may certainly be a contributing factor to the increasing number of these problems in young adults. Improving sleep health positively impacts blood pressure control and reduces the incidence of recurrence of cardiovascular complications. The American Heart Association (AHA) added sleep duration as a vital component of ‘Life’s Essential 8’ as a metric for cardiovascular health. Additionally, sleep deprivation can impair the body’s immunity and ability to fight infections. This leads not only to a higher risk of infections but also reduced response to vaccinations and immunisations which help to prevent infections.
The secretion of hormones such as ghrelin (which increases appetite) and leptin (which promotes satiety) is impaired in sleep disorders, and this, in turn, increases the risk of obesity. The concept of the ‘Thin Fat Indian’ is also evolving as non-obese Indians are noted to have high body fat and abnormal waist-to-hip ratios, despite having normal body mass index (BMI). These individuals are more prone to insulin resistance and metabolic disorders such as diabetes and dyslipidaemia (abnormal cholesterol proportions). Additionally, growth hormone, cortisol and sex hormones are secreted during sleep and altered rhythms may impair growth and lead to abnormal menstrual cycles in women and an increased incidence of infertility in both men and women.
Sleep is a vital process for brain restoration and regulation. Sleep health strongly correlates with mental health, and studies consistently highlight the association between sleep disorders and mental, behavioural and developmental disorders in all age groups. Lack of sleep is associated with depression, anxiety, cognitive impairments, and an increased risk of dementia in older adults. Insufficient sleep is highly prevalent among children and adolescents and is associated with poor mental health, including depressive symptoms and suicidal thoughts. Studies underscore the importance of addressing sleep as a modifiable risk factor in mental health and incorporating it into suicide prevention efforts. An increasing number of studies have shown that insufficient sleep and behavioural or emotional problems have reciprocal and mutually facilitating effects.
Under-recognised public health issue
Several factors contribute to the under-recognition of sleep deprivation as a public health issue:
Lack of awareness: Many individuals often devalue the seriousness of insufficient sleep and are unaware of the critical role sleep plays in overall health. Without proper education, people may not recognise the importance of sleep or understand the consequences of sleep deprivation. The increasing availability of information in digital and print media has been a boon and a bane as individuals are often unsure about the accuracy of the information they find.
Cultural norms: In many cultures, there is a prevailing emphasis on productivity and work, often at the expense of adequate rest. This cultural norm can lead to the normalisation of sleep deprivation, making it less likely to be recognised as a serious health issue.
Misconceptions about sleep needs: There is a common misconception that individuals can function optimally on minimal sleep. This belief can lead to underestimating the importance of sufficient sleep and may result in individuals not seeking help for sleep-related issues.
Underreporting and stigma: Sleep problems are often underreported due to stigma, or the perception that they are less serious than other health issues. This underreporting can result in a lack of data, making it challenging to advocate for public health initiatives focused on sleep health.
Inadequate screening and assessment: Healthcare providers may not routinely screen for sleep disorders, leading to underdiagnosis and undertreatment. Without proper assessment, sleep issues can go unrecognised and untreated, exacerbating their impact on health.
Overlooking the impact on mental health: Sleep deprivation is closely linked to mental health issues such as depression and anxiety. However, the bidirectional relationship between sleep and mental health is often overlooked, leading to missed opportunities for early intervention and comprehensive care.
Limited research and policy focus: Historically, there has been limited research and policy focus on sleep health compared to other health issues. This lack of emphasis can result in insufficient resources allocated to addressing sleep-related problems.
The solution
It is vital to recognise that sleep is a fundamental pillar of public health. Sleep deficiency not only impacts the individual’s health but has economic impacts related to negative effects on safety and productivity. The availability of comprehensive sleep health data remains sparse; however, models forecast a huge impact on economies. To mitigate the under-recognition of sleep deprivation, the following strategies are recommended:
Public education: Implement campaigns to inform the public about the importance of sleep and the risks associated with sleep deprivation. Employers need to be educated on the significance of rest and sleep on overall health and encouraged to provide a work environment that will not interfere with the employee’s ability to sleep adequately.
Healthcare integration: Encourage healthcare providers to routinely assess and address sleep issues during medical evaluations.
Policy development: Develop policies that promote healthy sleep habits, such as regulating work hours and creating environments conducive to rest.
Research and investment: Increase funding for research on sleep and its impact on health to inform evidence-based interventions. It is important to initiate efforts to collect and centralise standard sleep and circadian data in every country.
The Healthy People 2030 vision in the United States envisions a society in which all people can achieve their full potential for health and well-being across their life span. Its key priorities include the elimination of health disparities and addressing the social determinants of health, and encouraging cross-sector partnerships and collaborations.
The recent call for action from Prime Minister of India Narendra Modi emphasised the need for nationwide awareness and collective action to reduce obesity. The importance of sleep and early recognition and treatment of sleep disorders needs to be factored in while envisioning healthy people. Understanding the factors contributing to the under-recognition of sleep health and implementing targeted strategies can improve public health outcomes and enhance the quality of life for many individuals and a society that is happier, healthier and more productive.
Collaborative efforts among researchers, healthcare professionals and policymakers are essential to develop effective interventions and create beneficial policies. Sleep is relevant to all sectors of society and essential to the United Nation’s Sustainable Development Goals to ensure healthy lives and promote well-being for all ages. The WHO should recognise sleep as a health priority, which in turn would encourage countries to include this in their national health agendas.
(Dr. N. Ramakrishnan is senior consultant in sleep medicine, Apollo Hospitals, Chennai and Director, Nithra Institute of Sleep Sciences)
Published – May 20, 2025 05:28 pm IST