Health, money, work and life all play a critical role in an employee’s total well-being, according to a study from Fidelity Investments, based on responses from more than 9,000 workers and conducted in collaboration with researchers from the Stanford Center on Longevity and Cornell University.

The survey and behavioral analysis focused on the four domains of well-being, financial (debt, savings, insurance, budgeting); health (physical health, mental health, healthy behaviors); work (work/life balance, career status and opportunities, burnout); and life (personal satisfaction, sense of purpose, sources of stress, relationships) and found employees are struggling most in the financial domain, where 42% fall into the “unwell” category. Respondents were assigned a total well-being “score” for respondents within each domain of well-being—on a scale of zero to 100, an individual with a score of 61 or higher was considered “well,” while a score of 60 or below was considered “unwell.”

The research found stress related to work and finances impacted just about all employees in the survey, regardless of age, gender or income, and nearly all respondents (98%) reported feeling stressed in the past three months. Employees were most likely to report high levels of stress caused by their job (47% of participants), saving for the future (34%), paying off debt (33%) and their weight (30%).

Fidelity found a link between debt and work productivity. Employees with the highest levels of debt have twice the absenteeism of those with the lowest levels of debt, and miss an additional full week of work more when comparing the two groups. When looking at various types of debt, past-due medical bills were the leading indicator of workplace absenteeism, with one in eight workers reporting struggling with unpaid medical bills. In addition, 84% of the people with unpaid medical bills are financially unwell, two-thirds don’t get enough sleep and they miss an average of three additional days of work annually. More well-known forms of debt, like student loans and credit cards, were not a significant cause of employees missing work, Fidelity said.

When compared with workers who were not struggling with debt, workers with debt challenges are very unlikely to be in “excellent” health (only 14% of those struggling were in excellent health, compared with 35% of workers without debt issues); are significantly less likely to get enough sleep (35% vs. 54%) and are significantly more likely to be frequently stressed or anxious (46% vs. 26%).

The research suggests health and wealth are intrinsically connected. Achieving wellness in either the health or financial domains is extremely rare when facing challenges in the other—poor physical health generally correlates to poor financial health, and vice versa. According to the survey, only 4% of employees who had poor health ratings achieved strong financial wellness scores, yet 60% of people who are “well” in terms of health are also financially well.