A survey of 500 people by online dating service PARSHIP.co.uk found that more than half (51 per cent) of singles worried about not having a mate, while only a fifth (18 per cent) lost sleep over debt, with the same percentage saying they were concerned about work pressures.
Only seven per cent mentioned family problems, while three per cent said that they worried about getting ill, and none of the respondents said that they were bothered about global warming.
And the average singleton loses 28 nights of sleep a night worrying about not finding someone to share their lives with.
Dr Victoria Lukats, psychiatrist and PARSHIP.co.uk's relationship and dating expert said that people were likely to be single for longer than they would have been in the past because they had a higher expectation of what they wanted in a life partner.
She said: "It is surprising initially when you first look at it, but the figures speak for themselves, and it is the one thing that single people worry about most.
"There are more single people around now than ever before, partly because people are living longer and sometimes outliving their partner for longer, but also younger people are taking their time and settling down and an older age.
"People are more likely to have several relationships before they get married now, if they get married at all, and are less likely to settle down in their early twenties.
"I think people worry about being alone because as human beings we are naturally sociable, and our natural instinct it to have a partner.
"It is what most single people want, but they also have higher standards and are fussier about about who they end up with, so they end up being single for a longer amount of time.
"Also, the media has an influence as well, with so much coverage about people looking for the one and meeting their soulmate. Over the years the dating scene has changed and it's starting to become like that States, where finding the right person and settling down has become a preoccupation."
And she added that as well as not having to worry about finding a partner, people in relationships were also less stressed generally.
She said: "People are more likely to associate stress and its symptoms with debt and work pressures. However, the figures speak for themselves.
"Whilst many people see being single as a positive choice statistics show that the majority – 60 per cent of UK singles - would prefer to be in a relationship and are looking for that special person to share their life with.
"Scientific studies have shown that married men live longer than their single counterparts. This may be in part due to lower stress levels and the comfort that being in a long-term relationship can bring.
"In addition, people who have sex at least twice a week have also been shown to live longer, once again highlighting the benefits of being in a relationship.
"Unfortunately it's more headline-grabbing to say '£1 billion worth of debt is causing misery for thousands' when in fact loneliness is causing misery for six million singles."