Sleep disorders are among the most common health impairments worldwide and at the same time represent one of the most heterogeneous and inconsistently defined disease groups in medical research. It is estimated that around 20% to 30% of the adult population regularly report problems falling asleep or staying asleep, with a tendency toward increasing prevalence observed over recent decades. This development is discussed particularly in the context of modern living conditions characterized by high performance pressure, shift work, flexible working hours, and the increasing use of digital media. As a result, sleep duration is often reduced or sleep quality impaired, although sleep fulfills a central function for physical health, mental well-being, and cognitive performance. The prevalence of insomnia varies greatly depending on the definition. Table 1 illustrates the extent to which sleep disorders occur in society. The frequency of the most important sleep disorders shows a clearly tiered pattern: the most common is obstructive sleep apnea, followed by insomnia, and other significantly rarer conditions such as restless legs syndrome and narcolepsy.

Overall, sleep disorders impose a substantial social and economic burden, with estimated costs of around €423 billion per year in Europe (see Table 2). These total costs are distributed almost equally between direct costs (medical care, diagnostics, and treatment) and indirect costs, particularly productivity losses due to absenteeism or reduced performance. Informal caregiving also contributes to the overall burden, while intangible costs such as quality of life were not taken into account. At the level of individual disorders, a clear ranking emerges: the highest total costs are caused by sleep apnea at approximately €184 billion, followed by insomnia at around €158 billion and restless legs syndrome at about €79 billion. Narcolepsy (approximately €0.9 billion) and REM sleep behavior disorder (approximately €0.4 billion) contribute significantly less to the overall burden, but show notably high costs per patient. In particular, for RBD these amount to around €14,000 per year. 

The authors, however, emphasize several methodological limitations. These include heterogeneous diagnostic criteria, possible double counting in comorbid sleep disorders, and bias due to predominantly treated and therefore more severely affected patient groups. In addition, there is insufficient data availability in many countries, particularly in low- and middle-income regions, meaning that about one third of the estimates are based on statistical imputations. Overall, while the magnitude of the economic burden is robust, its precise quantification remains associated with uncertainty.

A complementary global perspective is provided by the systematic meta-analysis by Simonelli et al., which examines sleep health in low- and middle-income countries (LMIC). This includes 45 population-based studies with a total of over 231,000 adults from 20 countries. More than half of the data come from China and Brazil. Only a very small proportion of studies used objective measurement methods such as polysomnography or actigraphy, meaning that most results are based on self-reports.

The analysis shows that about 32.8 percent of adults in LMIC report poor sleep quality. At the same time, the heterogeneity of results is extremely high (I² ≈ 99.8 percent), with prevalences ranging from about 6 percent to 94 percent. Very high values were observed, for example, in Iran (up to 94.6 percent) and Argentina, while much lower values were reported in Ghana (about 6 percent) and in individual Chinese studies (8–16 percent). This enormous variation cannot be fully explained by geographical or demographic factors and indicates substantial methodological differences.

Sleep duration shows a similar pattern. On average, it is about 7.59 hours per night, which is within the international normal range. However, the range extends from about 6.57 hours in Argentina to over 8.6 hours in individual Chinese studies. In parallel, objective measurements sometimes show considerably shorter sleep times of around 5.7 hours, indicating a discrepancy between subjective perception and actual sleep duration.

In addition, it becomes clear that the assessment of sleep health is highly inconsistent internationally. Different measurement instruments such as the Pittsburgh Sleep Quality Index (PSQI) or simple single-item measures lead to considerable variation. Even within standardized instruments, cutoff values vary, further limiting comparability. Content-wise, there is also an uneven emphasis on different dimensions of sleep: while subjective sleep satisfaction is frequently studied, aspects such as sleep efficiency, alertness, and especially temporal sleep patterns remain significantly under-researched. Furthermore, there is a geographical bias, as large parts of the data come from only a few countries, while entire regions, particularly in Africa, are barely represented.

In summary, a consistent overall picture emerges: sleep disorders are highly prevalent worldwide, but extremely heterogeneous in their manifestation, measurement, and definition. While in Europe the economic burden of disease, with total costs of around €423 billion annually, is particularly emphasized, global evidence shows a widespread but highly context-dependent burden on populations. Despite differing perspectives, both approaches make clear that sleep disorders represent a substantial health, social, and economic challenge that has so far been insufficiently considered in public health strategies and global health models.

Sources: 

Bassetti, Claudio L. A., Luisa S. Welter, Mateo Montes‐Martinez, Nikolai Mühlberger, Paul Boon, Thomas Berger, Günther Deuschl, u. a. 2026. „Epidemiology and Economic Burden of Sleep Disorders in Europe“. European Journal of Neurology 33(2): e70463. doi:10.1111/ene.70463 Source.

Karna, Bibek, Abdulghani Sankari, und Geethika Tatikonda. 2026. „Sleep Disorder“. In StatPearls, Treasure Island (FL): StatPearls Publishing. Source (13. Juni 2026).

Simonelli, Guido, Nathaniel S. Marshall, Antigone Grillakis, Christopher B. Miller, Camilla M. Hoyos, und Nick Glozier. 2018. „Sleep Health Epidemiology in Low and Middle-Income Countries: A Systematic Review and Meta-Analysis of the Prevalence of Poor Sleep Quality and Sleep Duration“. Sleep Health: Journal of the National Sleep Foundation 4(3): 239–50. doi:10.1016/j.sleh.2018.03.001 Source.