People who check work emails after they've left the office and as soon as they wake up underestimate the damaging effects it has on their health and their relationships.
A study found 'flexible work boundaries' drive up stress levels, and push workers to become insular and less aware of social settings.
University employees surveyed by Virginia Tech University all had levels of anxiety that could be damaging to their health.
But few of them realized how severe that damage was - and none of them gauged that it left their partners incredibly stressed, too, the DailyMail reports.
"The competing demands of work and nonwork lives present a dilemma for employees, which triggers feelings of anxiety and endangers work and personal lives," said co-author William Becker, associate professor of management in the Pamplin College of Business.
The finding adds to growing evidence that "flexible work boundaries" often turn into "work without boundaries" - where bosses assume staff will never switch off.
Concern has already been raised about millions of employees who read messages last thing before they go to bed - and first thing when they wake up.
Becker's study finds the mere expectation results in strain and anxiety, for them and their partners or children.
The paper is the first to identify the phenomenon that has implications for office workers across the world. Previous studies have shown the stress of increased job demands leads to strain and conflict in family relationships.
This happens when the employee is unable to fulfill non-work roles at home "such as when someone brings work home to finish up," said Dr Becker.
But the latest findings show employees don't even have to engage in actual work during non-work time for the effect to be seen.
This is different to work-related demands that add to pressure, both physical and psychological, by requiring time away from home.
"The insidious impact of 'always on' organizational culture is often unaccounted for or disguised as a benefit - increased convenience, for example, or higher autonomy and control over work life boundaries," Dr Becker said.
"Our research exposes the reality, [that] 'flexible work boundaries' often turn into 'work without boundaries,' compromising an employee's and their family's health and well-being."
He said policies that reduce expectations to monitor electronic communication outside of work would be ideal. When that is not an option, the solution may be to establish boundaries on when electronic communication is acceptable during off-hours.
This could be by setting up off-hour email windows or schedules when employees are available to respond. Additionally, expectations should be communicated clearly.
Dr Becker said: "If the nature of a job requires email availability, such expectations should be stated formally as a part of job responsibilities."
Knowing these expectations upfront may reduce anxiety in employees and increase understanding from their family members, he said.
As for employees, they could consider practicing mindfulness, which has been shown to be effective in reducing anxiety. Mindfulness may help employees "be present" in family interactions, which could help reduce conflict and improve relationship satisfaction.
And, he added, mindfulness is within the employee's control when email expectations are not.
Dr Becker, who is presenting the study at an Academy of Management meeting in Chicago, added: 'Employees today must navigate more complex boundaries between work and family than ever before.
"Employer expectations during nonwork hours appear to increase this burden, as employees feel an obligation to shift roles throughout their nonwork time. Efforts to manage these expectations are more important than ever, given our findings that employees' families are also affected by these expectations."
A study of 132 people by psychologists at the University of Hamburg found during during times away from work when they were expected to be contactable they had higher levels of the stress hormone cortisol in their saliva.
Even when they were not required to be physically available at the office, the spike happened.
This is because technology means people are able to check their laptops, tablets and smartphone for emails, leading to a culture in which people must be constantly available for work, the researchers said.
In today's workforce, "job contacts and work availability outside regular business hours are associated with impaired wellbeing," the authors wrote in the study.
An earlier study also found checking work emails at home or taking a call from the boss at weekends could be damaging to health.
Another study of 57,000 people found that more than half worked outside their normal hours.
The researchers found that those who worked in the evenings and at weekends were more likely to complain of insomnia, headaches, fatigue, anxiety and stomach problems.
Muscular problems and cardiovascular issues were also linked to working outside of normal hours.
The scientists called for far stricter rules to stop work invading people's home life.