Work stress has two classic recipes, and both show up in heart studies

Key takeaways

• In a pooled analysis of 197,473 European workers, job strain, meaning high demands plus low control, was tied to a 23% higher risk of heart disease¹.
• Effort that isn’t matched by pay, respect or security was tied to a borderline 16% higher risk, and workers facing both stressors had a 41% higher risk².
• NIOSH, the federal workplace health research agency, says employers should fix working conditions before offering individual programs such as stress classes⁴⁵.
• Since 2024, Australian workers can decline after-hours contact unless refusing would be unreasonable, while in the U.S. the Surgeon General recommends limits on after-hours messages⁷⁸.
• Four-day-week pilots report less burnout, but the U.K. pilot had no comparison group, relied on self-reports and was organized by advocacy groups⁹.

Researchers once followed 10,308 London civil servants for about five years³. They asked each worker how much say they had over their own work. They also asked personnel managers to rate the control each job allowed, so the answer didn’t depend only on how workers felt³.

Workers whose control was low at two checks, about three years apart, had nearly twice the odds of a new heart problem as those whose control was high both times³. That held after the team accounted for job grade and classic risk factors³.

The surprise was what didn’t matter. High job demands, on their own, showed no significant link to heart trouble in that study³.

That finding comes from the Whitehall II study, published in 1997³. Larger studies since then point the same way: pressure alone isn’t the whole story. Pressure without a steering wheel, or effort without a fair return, is where the strain seems to live.

If you value prevention and believe health grows from the conditions of daily life, this research is on your side. It points to changes in the job itself, not just in the worker.

Two models explain most of what researchers call work stress

The first is the demand-control model, often called Karasek’s job strain model¹. It asks two questions. How heavy are your demands, such as workload and conflicting requests? And how much control do you have, such as freedom to make decisions and chances to learn new things¹?

A job is called high strain when demands are high and control is low¹. In the big European studies, about 15% of workers fit that description¹.

The second is the effort-reward imbalance model, set out by Siegrist in 1996; he later co-authored the 2017 study described below². Effort includes pace, workload and hours. Rewards include pay, but also respect, recognition, a shot at promotion and job security².

Imbalance means you keep putting in more than you get back. In the 2017 study, nearly a third of workers (31.7%) met that definition, ranging from 8% to 51% across the cohorts².

The two models overlap but aren’t the same. A well-paid surgeon may have high demands and high control. A warehouse worker paced by a scanner may have high demands, little control and little security.

Both patterns track with heart disease, at a modest level

In 2012, the IPD-Work consortium pooled raw data from 13 European cohort studies, groups of people tracked over years¹. The 197,473 workers had no heart disease at the start and were followed for an average of 7.5 years¹.

Workers with job strain had a 23% higher risk of a first heart attack or death from coronary heart disease¹. After accounting for socioeconomic status, the excess was 17%¹.

The team checked a common worry: that early, undiagnosed illness makes a job feel harder. When they dropped heart events from the first three years, the link got slightly stronger, at 31%¹.

To put that in perspective, the authors estimated that job strain accounts for about 3.4% of heart disease cases, if the link is causal¹. They cited estimates of 36% for smoking and 12% for physical inactivity¹. Work stress matters, but it isn’t the biggest heart risk most people face.

One detail stands out. Studies that had already been published showed a 43% higher risk, while unpublished data showed 16%¹. That gap suggests published research can overstate a finding, which is one reason pooled raw data are valuable.

Effort-reward imbalance showed a similar pattern. A 2017 analysis of 90,164 workers in 11 European cohorts found a 16% higher risk of heart disease over about 10 years, a result at the edge of statistical significance². Workers with both job strain and imbalance had a 41% higher risk than workers with neither². About 1 in 10 workers had both².

These are observational studies, so they show links, not proof¹². Stress was measured only once, mostly by self-report, and the workers were mainly in Northern and Western Europe¹². A later article in this library covers how long-running stress wears on the body.

U.S. guidance favors fixing the job before fixing the worker

The National Institute for Occupational Safety and Health (NIOSH) runs a program called Total Worker Health⁴. It joins traditional safety protection with efforts to prevent illness and support well-being⁴.

NIOSH ranks workplace fixes from most to least effective⁴:

1. Eliminate conditions that harm health, such as harmful supervision practices.
2. Substitute healthier policies and management practices.
3. Redesign the work, for example with flexible schedules.
4. Educate workers with training and resources.
5. Encourage personal changes.

In a 2024 post, NIOSH put it plainly: programs should use individual-level approaches only after addressing organizational ones⁵. Its list of issues includes work intensification, safe staffing, overtime, long hours, shift work and stressful job monitoring⁴.

In 2021, the International Organization for Standardization published ISO 45003, a set of guidelines for managing psychosocial risks, meaning work features that can harm mental health⁶. It covers problems such as excessive pressure, poor communication, poor leadership and organizational culture⁶.

The U.S. Surgeon General’s 2022 framework names five essentials for workplace mental health: protection from harm, connection and community, work-life harmony, mattering at work, and opportunity for growth⁷. It urges employers to give workers more say over how work is done, to check whether staffing matches demands, and to cut long hours⁷.

Our guide to staying well while working full time covers burnout‘s official definition and the counseling, accommodation and leave options that can help. Our history of workplace wellness explains why typical perks rarely move health measures.

The right to disconnect is now law in Australia

Since August 26, 2024, employees of Australian businesses with 15 or more workers have had a legal right to disconnect⁸. Workers at smaller businesses gained it on August 26, 2025⁸.

The law doesn’t stop employers from calling or emailing⁸. It lets employees decline to check, read or answer calls and messages outside their working hours, unless saying no would be unreasonable⁸.

Whether refusal is reasonable depends on the reason for the contact, how disruptive it is, whether the worker is paid to be on call, the worker’s role, and personal duties such as caregiving⁸. Disputes go first to the workplace, then to the Fair Work Commission⁸.

In the U.S., the Surgeon General’s framework recommends policies that limit after-hours digital messages, such as after a set evening hour and on weekends⁷. The Occupational Safety and Health Administration (OSHA) suggests managers model “quiet hours” and make clear that email can wait¹³.

Workers want this. In APA’s 2023 Work in America survey, cited by NIOSH, 95% of workers said it matters that employers respect the boundary between work and personal time⁵. Whether disconnect laws lower stress or heart risk hasn’t been shown in the sources we reviewed.

Four-day weeks: encouraging results with real caveats

In 2022, 61 British companies and about 2,900 employees tried a shorter week for six months, with no pay cut⁹. The pilot was organized by two four-day-week advocacy groups and the Autonomy Institute, which also wrote the report⁹. A foundation partly funded the project, and researchers at Boston College and the University of Cambridge co-wrote the report⁹.

By the end, 56 of the 61 companies were continuing, and 18 had made it permanent⁹. On surveys, 71% of employees reported lower burnout and 39% reported less stress⁹. Fatigue and sleep problems also eased for many⁹.

Read the fine print, though:

• No comparison group. Researchers compared workers with themselves before the trial⁹.
• Self-reported outcomes. Burnout and stress came from employee surveys, and only 58% answered the final one⁹.
• Mixed results. About 22% reported higher burnout⁹.
• Hours fell less than the name suggests. The average week went from 38 to 34 hours, not 32⁹.
• Some gains could be chance. Drops in sick days and resignations weren’t statistically significant⁹.
• Selection. Companies chose to join, so they may have been well suited to the change⁹.

Scientific American called a 2025 study the biggest trial yet. That July, a team led by Boston College sociologist Wen Fan reported in Nature Human Behaviour on 141 companies and 2,896 workers in six countries, including the United States¹⁰. Burnout fell, and job satisfaction and mental and physical health improved¹⁰.

The caveats were familiar. Companies volunteered, every outcome was self-reported, and the authors called for randomized trials¹⁰.

Juliet Schor, a Boston College sociologist and co-author of the U.K. report, served on the academic board of 4 Day Week Global as of 2022⁹¹¹. That nonprofit promotes the four-day week and coaches companies through the pilots¹¹.

None of this means the results are wrong. It means they come from willing companies and rest mostly on employees’ own reports, gathered by researchers working alongside advocates. A randomized trial would settle more.

Where you work matters less than whether it fits you

Remote and hybrid work reshaped many jobs. In 2021, 38% of employed Americans did some or all of their work at home, up from 24% in 2019, according to federal data cited by OSHA¹³.

The setting itself may matter less than fit. In the American Psychological Association’s 2025 Work in America survey of 2,017 workers, the type of arrangement, whether in person, hybrid or remote, had no significant link with job satisfaction¹².

What mattered was getting the arrangement you wanted. Workers in their preferred setting were less likely to feel tense during the workday, 37% compared with 51%¹². They were also less likely to say work stress hurt their sleep, 28% compared with 40%¹².

Each setting has its own strains. OSHA notes that remote workers can feel isolated, and many feel on call around the clock¹³. A study cited by OSHA found that the workday got longer for people working from home¹³.

Uncertainty weighs on everyone. In the same APA survey, 54% said job insecurity significantly affected their stress at work¹².

What the evidence shows

Claim	What studies found	Evidence level
Job strain (high demands, low control) raises heart disease risk	23% higher risk in 197,473 workers; held after excluding early cases1	Strong evidence (modest, observational)
Low control matters even when measured by someone else	Managers’ ratings predicted heart problems about as well as workers’ own3	Promising but early (one large cohort)
Effort-reward imbalance raises heart disease risk	16% higher risk, borderline; 41% with both stressors2	Promising but early
Four-day weeks cut burnout	Self-reported gains in volunteer companies; no comparison group in the U.K. pilot910	Promising but early
Working in your preferred arrangement eases stress	Lower tension and better sleep in one large survey12	Promising but early
Right-to-disconnect laws improve health	Laws are new; no outcome data in our sources8	Not enough evidence

Your work stress map

This is our own tool, built on the two models and the Surgeon General’s framework¹²⁷. Fill in one row at a time.

Area	Ask yourself	One change to ask for	One change you can make
Demands	Is my workload doable in my paid hours most weeks?	A clear ranking of priorities for this month	List every task due in the next two weeks
Control	Do I have a say in how, when and in what order I work?	Choice over the timing of one recurring task	Block one hour a day for focused work
Effort	Am I regularly working unpaid evenings or weekends?	An agreed rule for after-hours messages	Turn off work notifications at a set time
Reward	Do pay, thanks or growth match what I give?	A review of pay, title or training	Write down your wins to bring to a review
Support	Who at work has my back when things go wrong?	Regular one-on-one check-ins	Have coffee with one coworker this week

Look for the row with the biggest gap. That’s your first conversation.

A script for raising workload with your manager

These are our words. Adjust them to fit your job.

1. Open with the goal. “I want to do good work on the projects that matter most. Right now I have more due than I can do well, and I’d like your help choosing.”
2. Show the facts. “Here’s my list for the next two weeks, with due dates and rough hours. It adds up to about [number] hours, and I have [number].”
3. Ask for a ranking. “Which two of these matter most? Could the others move, be shared or be dropped?”
4. Ask for one piece of control. “Could I set the timing on [task], as long as it’s done by Friday?”
5. Set a boundary together. “Can we agree that messages after [time] can wait until morning unless something is truly urgent? What counts as urgent?”
6. Close with a check-in. “Can we look at this again in two weeks?” Afterward, send a short email that sums up what you agreed.

If the problem is a toxic culture rather than a busy month, talk with human resources or a trusted mentor before you push alone.

When work stress needs more than a schedule change

Stress at work can spill into health. See a clinician or mental health professional if:

• symptoms after a stressful or frightening event don’t improve over time or start to interfere with daily life, according to the National Institute of Mental Health¹⁴;
• you pull away from family and friends, or have physical symptoms such as headaches, stomach problems or a racing heart, which NIMH lists as warning signs¹⁴;
• you keep drinking or using drugs to cope even though it causes harm, which OSHA lists as a sign of a substance use disorder¹⁵;
• after a frightening event at work, flashbacks, nightmares, trouble sleeping or feeling easily startled last a long time or disrupt daily life, which OSHA says may signal a condition that needs professional help¹⁵.

Prolonged stress and job loss are among the risk factors for suicide that OSHA lists¹⁵. If you or someone you know is struggling or thinking about suicide, call or text the 988 Suicide & Crisis Lifeline at 988, any time¹⁵. In a life-threatening emergency, call 911¹⁴.

Questions readers ask

The bottom line

Work stress isn’t just a feeling. Large studies tie two patterns, high demands with little control and big effort with little reward, to a modestly higher risk of heart disease. Federal guidance, especially from NIOSH, puts changes to the job ahead of coping classes.

Four-day weeks look promising, though the evidence so far is self-reported, and disconnect laws are too new to judge. In the meantime, map your own job, pick the biggest gap and ask for one concrete change. Get help early if stress starts to take over your health or your days.

Keep exploring: resilience after trauma, chronic stress effects and stress and insomnia.

Related reading

• Full-time workers average under three free hours a workday, so build health into the rest
• Wellness started as a big idea about thriving before office programs made it small
• One in seven workers clocks in during off-hours, and sleep is the first thing to anchor
• Shift work disorder is treatable, though even the approved pills leave you sleepy
• Most people stay steady after trauma, and resilience courses add less than promised

Sources

1. Kivimäki M, Nyberg ST, Batty GD, et al., for the IPD-Work Consortium. “Job strain as a risk factor for coronary heart disease: a collaborative meta-analysis of individual participant data.” The Lancet, 2012;380:1491–1497. lshtm-eprints-repo-prod.lshtm-eprints.cdl.cosector.com
2. Dragano N, Siegrist J, Nyberg ST, et al. “Effort–reward imbalance at work and incident coronary heart disease: a multicohort study of 90,164 individuals.” Epidemiology, 2017;28(4):619–626. pubmed.ncbi.nlm.nih.gov
3. Bosma H, Marmot MG, Hemingway H, Nicholson AC, Brunner E, Stansfeld SA. “Low job control and risk of coronary heart disease in Whitehall II (prospective cohort) study.” BMJ, 1997;314:558. pubmed.ncbi.nlm.nih.gov
4. Lee MP, Hudson H, Richards R, Chang CC, Chosewood LC, Schill AL. “Fundamentals of Total Worker Health Approaches.” NIOSH Publication No. 2017-112, December 2016. cdc.gov
5. National Institute for Occupational Safety and Health. “Supporting Mental Health in the Workplace.” NIOSH Science Blog, April 15, 2024. cdc.gov
6. International Organization for Standardization. “Mental health in the workplace” (on ISO 45003:2021). ISO news, June 8, 2021. iso.org
7. Office of the U.S. Surgeon General. “The U.S. Surgeon General’s Framework for Workplace Mental Health & Well-Being.” HHS, 2022. hhs.gov
8. Fair Work Ombudsman (Australian Government). “New right to disconnect laws.” Updated August 26, 2025. fairwork.gov.au
9. Lewis K, Stronge W, Kellam J, Kikuchi L (Autonomy); Schor J, Fan W, Gu G (Boston College); Kelly O; Frayne D, Burchell B, et al. (University of Cambridge). “The results are in: The UK’s four-day week pilot.” Autonomy, February 2023. autonomy.work
10. Ahart J. “The Biggest Trial Yet Confirms Four-Day Workweek Makes Employees Happier” (on Fan W, et al., Nature Human Behaviour, July 21, 2025). Scientific American, July 21, 2025. scientificamerican.com
11. Smith S. “A four-day work week?” Boston College News, December 2022. bc.edu
12. American Psychological Association. “2025 Work in America Survey: The Experience of Working in America During Times of Change.” APA, July 2025. apa.org
13. Occupational Safety and Health Administration. “Workplace Stress: Hybrid Workforces.” U.S. Department of Labor, accessed October 2026. osha.gov
14. National Institute of Mental Health. “Coping With Traumatic Events.” Last reviewed May 2024. nimh.nih.gov
15. Occupational Safety and Health Administration. “Workplace Mental Health.” Fact sheet OSHA 4395-01, 2024. osha.gov