Fatigue Manifests as "Cold Sensitivity" and "Brain Fog": 38.12 Million with Cold Sensitivity, 19.66 Million with Brain Fog - The Reality of Widespread Fatigue-Related Symptoms

The Japan Recovery Association (Secretariat: Atsugi City, Kanagawa Prefecture, Representative Director: Hideki Katano), in collaboration with the Japanese Society of Fatigue Science and VENEX Inc., conducted the "Kokoro no Tairyoku Sokutei" (Mental Fitness Measurement) health and lifestyle survey in May 2026. This annual survey, conducted since 2017, targets 100,000 to 140,000 people nationwide (50,000 to 70,000 men and women aged 20-79). The survey continuously investigates fatigue levels, lifestyle habits, and "fatigue-related symptoms" such as physical, cognitive, and sensory functional impairments that accompany fatigue.

In the 2026 survey, "cold sensitivity" (42.0%) was the most common fatigue-related symptom, affecting an estimated 38.12 million people. "Eye strain" (37.8%) and "stiff neck/shoulders" (34.9%) were also prevalent, with over 30 million people experiencing these issues. Furthermore, "brain fog" affected 21.6% of the population, equivalent to 19.66 million people, revealing that fatigue impacts not only the body but also cognitive functions.

*Commercial use of data is limited to companies that have purchased the "Recovery White Paper 2026".

*Fatigue-related symptoms include, in addition to general fatigue, conditions such as "dizziness," "headaches," "palpitations/shortness of breath," "menopause symptoms," "menstrual pain/irregularity/PMS," "brain fog," "hearing loss/difficulty hearing," and "cold sensitivity."

*This report is supplemented by data from the "Physical Ailments" announcement in June 2024.

https://prtimes.jp/main/html/rd/p/000000041.000085299.html

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【Survey Summary】

Cold sensitivity was the most common symptom at 42.0%, affecting an estimated 38.12 million people.

Eye strain (37.8%) and stiff neck/shoulders (34.9%) affected over 30 million people.

Brain fog affected 21.6%, or an estimated 19.66 million people.

Women reported higher rates of cold sensitivity (50.5%) and stiff neck/shoulders (38.0%) compared to men.

Men reported higher rates of hearing loss (33.3%) and brain fog (23.7%) compared to women.

Menstrual pain/PMS (34.4%) and menopause symptoms (30.0%) were significant issues for women.

*Population estimates are based on the Ministry of Internal Affairs and Communications Statistics Bureau's population projection as of April 1, 2026 (estimated), with 91.33 million people aged 20-79, adjusted by gender and age group coefficients. Source URL: https://www.stat.go.jp/data/jinsui/new.html

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【Reference】

Economic Loss Due to Fatigue: A Shocking ¥15.2 Trillion Annually

Analysis based on health-related costs defined presenteeism-related losses at ¥37.0579 trillion. Of this, fatigue-related economic losses were calculated at ¥15.2154 trillion (41.1% of the total).

*This figure is derived by considering the impact of fatigue on the economic loss per employee (total health-related costs) of approximately ¥565,000 due to presenteeism.

*Commercial use of data is limited to companies that have purchased the "Recovery White Paper 2025".

~ "Recovery (Rest & Anti-Fatigue) White Paper 2025 Report" Vol. 3 ~

Economic losses due to fatigue reach ¥15 trillion annually: First visualization of corporate fatigue costs through a nationwide survey of 100,000 people, resulting in an annual loss of ¥227,000 per person.

https://prtimes.jp/main/html/rd/p/000000081.000085299.html

Increasing "Stress and Autonomic Nervous System Imbalances": Fatigue-Related Symptoms Diversify

From 2019 to 2026, while traditionally common symptoms like "stiff neck/shoulders" (38.2% to 34.9%) and "eye strain" (40.5% to 37.8%) showed a slight downward trend, an increase in symptoms linked to the autonomic nervous system and stress was notable. Specifically, "dizziness" rose from 11.8% to 15.6%, "palpitations/shortness of breath" from 12.9% to 15.6%, and "stomach/intestinal issues" from 17.4% to 19.1%. "Menopause symptoms" increased to 29.0%, and "menstrual pain/irregularity/PMS" to 34.4%, indicating an upward trend in women's specific health issues. Furthermore, "hearing loss/difficulty hearing" surged from 20.9% in 2025 to 28.4%, and "cold sensitivity" reached its highest level among all symptoms at 42.0%. "Brain fog" remained high at 21.6%, revealing that modern fatigue extends beyond the physical to affect the autonomic nervous system, brain function, and sensory organs.

*Commercial use of data is limited to companies that have purchased the "Recovery White Paper 2026".

Based on the population estimates from the Statistics Bureau of the Ministry of Internal Affairs and Communications, when converted to the population aged 20-79, the fatigue-related symptoms in 2026 were most prevalent in "cold sensitivity (low body temperature)" at 38.124 million people, followed by "eye strain" at 34.407 million, "stiff neck/shoulders" at 31.768 million, and "lower back pain" at 27.341 million. Additionally, stress, autonomic nervous system, and sensory function-related issues such as "menopause symptoms" (26.678 million) and "hearing loss/difficulty hearing" (26.151 million), and "brain fog" (19.657 million) are also widespread. "Palpitations/shortness of breath" and "dizziness" each affected approximately 14 million people, indicating that Japanese people's fatigue is no longer just physical but manifests in a diverse range of ailments.

*Commercial use of data is limited to companies that have purchased the "Recovery White Paper 2026".

Women More Prone to "Cold Sensitivity" and "Stiff Neck/Shoulders"; Men to "Hearing Loss" and "Brain Fog"

Comparing fatigue-related symptoms by gender in 2026, "cold sensitivity (low body temperature)" exceeded 50% for women (50.5%), significantly higher than men (33.2%). "Eye strain" (women 39.0%, men 36.5%), "stiff neck/shoulders" (38.0%, 31.8%), "headaches" (21.0%, 19.9%), and "constipation/diarrhea" (22.0%, 21.7%) also tended to be higher in women. Furthermore, "menstrual pain/irregularity/PMS" (34.4%) and "menopause symptoms" (30.0%) represent significant challenges unique to women. On the other hand, men reported significantly higher rates of "hearing loss/difficulty hearing" (33.3%) compared to women (23.8%), and "brain fog (difficulty thinking clearly)" was also higher in men (23.7%) than in women (19.6%). "Palpitations/shortness of breath" (16.8%) and "stomach/intestinal issues" (20.0%) were also higher in men, suggesting that the impact of stress and fatigue on cognitive function and the autonomic nervous system is also prevalent in men. These results indicate that women are more characterized by circulatory and hormonal-related issues, while men are more affected by sensory and cognitive function-related ailments, highlighting the importance of gender-specific fatigue countermeasures and recovery support.

*Commercial use of data is limited to companies that have purchased the "Recovery White Paper 2026".

【Kokoro no Tairyoku Sokutei 2026 Survey Overview】

Survey Name: "Kokoro no Tairyoku Sokutei 2026"

Period: May 2026

Survey Target: 100,000 people nationwide aged 20-79 (50,000 men and 50,000 women)

Method: Internet Survey

Survey Items: 10 questions

*Fatigue Level Items: Based on the Ministry of Health, Labour and Welfare's "Stress Check" Item B, custom-processed and scored.

*Sample size: 50,000 per gender, with over 500 samples secured for each prefecture. Weight adjustments were then made based on population ratios (prefecture, age group, employment status).

【Japan Recovery Association Overview】

Location: 4F Asaoka Building, 4-4-13 Nakamachi, Atsugi City, Kanagawa Prefecture

President: Yasuyoshi Watanabe (Project Professor, Graduate School of Science, Technology and Innovation, Kobe University; Professor Emeritus, RIKEN; Advisor, Center for Health Science Innovation, Osaka Metropolitan University; Professor Emeritus, Osaka City University; Chairman, Japanese Society of Fatigue Science; Chairman, Japan Brain Fitness Promotion Association; CEO, Genki Vital Academy Inc.)

Vice President: Kei Mizuno (Project Professor, Graduate School of Science, Technology and Innovation, Kobe University; Project Professor/Vice Director, Center for Health Science Innovation, Osaka Metropolitan University; Director/Secretary General, Japanese Society of Fatigue Science)

Advisors: Yasuo Otani (Chairman, Kanagawa University of Health and Welfare; Former Special Advisor to the Cabinet Office)

Hideaki Matsuki (Professor Emeritus, Tokai University; Director, Japan Council for Quality Health Care)

Masaki Taba (Former Professor, School of Health Sciences, Tokai University)

Representative Director: Hideki Katano, Ph.D. (Medicine) (Visiting Researcher, Hakujikai Geriatric Research Institute; Advisor, Genki Vital Academy)

Affiliation: Genki Vital Academy (Germany)

URL: https://www.recovery.or.jp/

【Definition of Recovery】

Recovery is the restoration of functions that have declined in physical and mental activity capacity, and the accumulation of vitality, which serves as physiological and psychological capital, in preparation for the next endeavor through rest.

<Contact for Media Inquiries>

Public Relations Secretariat, Japan Recovery Association

Email: info@recovery.or.jp