When you’re sick, your body feels bad, your head is fuzzy, and you may even be contagious. When you’re sick and you have to work, you feel miserable. But about four in 10 workers can’t take a day off for an illness or medical emergency without risking their day’s pay. And they bear much of the cost not in dollars but in mental and emotional strain.

A newly published study on the long-term psychological implications of paid sick leave, which is standard in many wealthy countries, reveals that, while the pressure to go to work sick is obviously linked to poorer physical health, the mind may suffer a parallel burden. When a lack of health protections clashes with a sudden illness or a family member’s medical crisis, workers can become exhausted, less productive at work, and more prone to negative temperament at work and at home. This low-grade malaise might not land one in the hospital, but, with more than 51 million workers nationwide denied a single paid sick day, the burden feeds into the country’s mental-health epidemic.

According to survey analysis by researchers at Cleveland State and Florida Atlantic Universities, workers without paid leave were more likely to report stress at work than those with paid leave, and those overstressed workers were some 45 percent more prone to feel that “distress interfered a lot with their life or activities.”

Surveys of workers across the social and income spectrum reveal a dangerous loop between physical and psychological ailments: A lack of basic job benefits like paid sick time could contribute to contagion and dipping productivity, perhaps even injury at hazardous worksites. When sickness inhibits work performance, economic and emotional instability follow, under threats of punishment from an unforgiving boss, or fear of losing that promotion.

The researchers note, that the downward spiral of ill health and mental stress, resulting in ”sad, nervous, restless, hopeless symptoms,” ironically can cost workers the opportunity to attain better jobs with benefits like paid leave. Such cumulative stressors could not only limit future social mobility but also deplete a struggling household’s emotional and financial well-being.

Typical health-related stressors affect home life as well—for example, when a sudden illness throws off a school schedule, or forces relatives to shoulder the burden at home, amid escalating household medical costs. Patricia Stoddard-Dare, professor of social work at Cleveland State University and co-author of the study, noted that when work performance suffers, “A worker without sick-leave benefits could be fired for this. It is enough to throw some families into poverty.” Basically, poor physical health begets poor mental health and vice versa, and our current workplace standards neglect both, while punishing workers for the consequences.

The types of workers who lack paid sick leave are also likely to lack a lot of other workplace protections, and workers without paid sick leave are disproportionately poorer, younger, and have less formal education. Fewer than half of Latino workers have paid sick days, compared with 60 percent of the workforce as a whole, and there are similar gaps between private- and public-sector workers, who typically have higher union representation and more comprehensive benefits.

Four in five part-timers working fewer than 20 hours a week lack paid sick days. Ironically, many work in service jobs that are particularly hazardous when, for example, the bartender is sniffly or flu-stricken home-care aides tend to frail seniors. Even among relatively privileged white workers, a stark gap emerges between men and women.

Across the workforce, researchers found a lack of paid medical leave to pose a distinct “structural disadvantage” for marginalized workers. Conversely, the surveys indicate “the potential value of paid sick leave as an intervention to promote behavioral health,” on a workplace-wide basis or as labor law. Removing the impossible trade-off between income and care could significantly boost public health and psychological well-being—a holistic social benefit that provides for a healthier, more content workforce, with possibly less employee turnover and greater productivity. Comprehensive paid-leave policies, whether just a few paid sick days a year, or longer-term paid medical- and family-leave programs, could also help workers protect long-term psychological well-being.

Lawmakers are realizing that paid medical leave benefits make sense for business and public health. Seven states, various cities, and Washington, DC, have launched paid-sick-time policies (although conservatives have sought to pass regressive laws preempting such policies). Legislation and ballot initiatives have been proposed in dozens of localities, often coupled with grassroots movements for fair-scheduling and minimum-wage campaigns stemming from a national movement for fair workplace standards. The proposed federal Healthy Families Act would establish a national standard of seven paid sick days for workplaces with 15 or more workers.

Rising public pressure has spurred several large national employers to voluntarily offer paid leave; perhaps they have realized the financial cost is, on balance, negligible. Although the powerful business lobby against paid-leave policies has often cited concerns about unnecessary costs or excessive absenteeism, experiences with paid-sick-time rules suggest that forcing workers to do their jobs in poor health does more harm than good. Studies show the potential financial cost is typically offset by the social benefits of a more stable, productive workforce. Research links paid sick time to slowing the spread of diseases. It just makes sense that cost-free time off work for self-care or family-health needs can be a crucial ounce of prevention, and a health investment on a societal scale.