American workers feel more isolated than ever, with younger workers feeling loneliness more than their older colleagues.

Three out of every five adults say they sometimes or always feel lonely, according to health insurance company Cigna, which has created a U.S. Loneliness Index for the second year in a row, based on a survey of 10,000 adults.

The numbers are shockingly high for young adults. Seventy-three percent of workers aged 18-22, known as Generation Z, report sometimes or always feeling alone - up from 69% a year ago.

3 out of 5 adults, or 61%, said that they sometimes or always feel lonely

'We had a hypothesis that society — the U.S. specifically — was dealing with an elevated level of loneliness, disconnection,' said Cigna CEO David Cordani to CNBC.

'We can start to see those disconnections manifest themselves in other health issues showing up for individuals … whether you think about it through the lens of depression, stress … or more heavy, complex behavioral issues.'

One reason younger people may feel more isolated is their use of social media, the report states.

The study found the more time people spent on social media, feelings of loneliness also increased.

Among workers 18-22, 73% report sometimes or always feeling alone, up from 69% in 2019

The responses from seven out of 10 heavy social media users saw 71% report feelings of loneliness, up from 53% a year ago.

Of light social media users, 51% said they felt lonely, up from 47% a year ago.

Younger people who have just begun new jobs also reported feeling alienated, far more than workers who had been employed for more than 10 years or so.

Some 66% of workers says they felt lonely compared to 40% who had been in the job for a decade.

Entry-level workers appeared to feel loneliness it the most, with more than half saying that there was nobody at work they could turn to.

But even the bosses felt neglected with 56% of senior executives saying there was nobody they could speak to and 69% suggesting that nobody really knows them that well.

There is a greater feeling of loneliness among people who use social media more. At work, men appear to feel much more isolated than women

'They're more isolated from other employees. If we think about the way to mitigate this — which is having coffee, having lunch with your co-workers — that's not a typical workplace culture for a lot of senior executives,' said Cigna Chief Medical Officer Dr. Douglas Nemecek. 'So, it's something that we have to think about and work on.'

The genders also revealed their own split, with 40% of men feeling far more isolated at work compared to 29% of women.

The study also suggests that there had been an increase in loneliness levels all round.

Some 63% of men said they had feelings of loneliness compared compared to 53% a year ago. The increase was not as bad for women with 58% reporting loneliness, up from 54% in 2019.

Loneliness at work can also go on to affect productivity with researchers estimating that those employees who feel socially isolated miss work as much as five times more than co-workers because of stress, and are more likely to contemplate quitting their jobs.

Conversely, the study saw that people who spend time interacting face to face with others at work feel less lonely or alienated.

'In-person connections are what really matters,' says Nemecek to NPR. 'Sharing that time to have a meaningful interaction and a meaningful conversation, to share our lives with others, is important to help us mitigate and minimize loneliness.'

The oldest workers, Baby Boomers and those older than 72 are most likely to feel as though they have people they can turn to at work. Just 18% of over 70s reporting feeling alienated while on the job.