Loneliness among Americans has reached "epidemic levels," according to health service company Cigna's U.S. Loneliness Index, released Tuesday.
The index, which surveyed over 20,000 U.S. adults, found that nearly half of survey respondents reported sometimes or always feeling alone (46 percent) or left out (47 percent) and younger generations feel much lonelier than older ones.
The survey also revealed that striking the right work-life balance can combat feelings of isolation, with those working less than desired actually feeling lonelier than those working more than desired.
For Cigna's report, survey respondents were evaluated on their loneliness using the UCLA Loneliness Scale, a 20-item questionnaire that was developed to assess subjective feelings of loneliness and social isolation.
Gen Z adults surveyed (ages 18 to 22), are the loneliest, according to the report. More than half of Gen Zers identified with 10 of the 11 feelings associated with loneliness, according to the survey, including feeling like people around them are not really with them (69 percent), feeling shy (69 percent) and feeling like no one really knows them well (68 percent).
"While we know that this is a group that is making life changes, these findings give us a surprising understanding of how this generation perceives themselves," Douglas Nemecek, M.D., chief medical officer for Behavioral Health at Cigna, tells CNBC Make It in an email. "It's something that we need to explore to understand how we can address it. And that's what we're planning to do."
Loneliness seems to lessen with age: Millennials (adults ages 23 to 37, according to the study) are not quite as lonely as Gen Z, but lonelier than Baby Boomers (ages 52 to 71). People in the Greatest Generation (ages 72 and up, according to Cigna's report) are least likely to report having feelings of loneliness.
Though the survey found that social media does't have much of an impact on loneliness — those who defined themselves as very heavy users of social media had similar loneliness scores as those who say they never used it — other things you do during the day have an impact.
Those who are employed, for example, are less lonely than students and the unemployed, the latter of whom have the highest feelings of loneliness. (Retired people were the least lonely, because many of them seem to have found a supportive community, says Nemecek, and homemakers fell in the middle of the spectrum.)
"The fact is that we spend a lot of time at work, so it's very natural that this time — and the relationships you build with co-workers — truly matter," says Nemecek, explaining the findings. "[S]o it's critical that employers create a space where employees can connect face-to-face and form meaningful relationships with their co-workers."
In fact, one way to combat loneliness, the survey found, is to work the right amount — those who reported doing so were the least likely to be lonely, while those who work more than desired had a three point increase in loneliness and those who work less than desired had a full six point increase in loneliness.
While Nemecek says the optimal level of hours of work per week is largely dependent on the individual and their line of work, "Balance is critical," he says. "It's important that managers keep watch over how much time employees spend at the office."
The survey also found that striking the right balance of sleep, exercise, socializing with friends and family and "me time," can help alleviate feelings of loneliness.
Don't miss: Air pollution can be bad for the brain — these are the cleanest and the smoggiest places in America
Like this story? Like CNBC Make It on Facebook