The study reveals that the internet is a vital lifeline to people, offering a social network they would not normally have, even if they never end up meeting those whom they befriend online.
Research commissioned by the Cystic Fibrosis Trust in the UK shows that users of Facebook and other social networking sites typically have 121 online friends, versus 55 physical buddies.
30 percent of those who took part in the survey spend at least two hours on social networks interacting with friends, and one in 10 people has either met their best friend online or believe they will meet people who will become lifelong friends on the web.
"For most people, the internet is a way of keeping in touch with loved ones and friends but for people who are isolated due to illness, it plays a more vital role and can often act as a lifeline," Helen Oxley, consultant clinical psychologist at Manchester Adult Cystic Fibrosis Centre, Wythenshawe hospital, told The Guardian.
The study also showed that people tend to be more honest with friends online than when faced with friends.
"In wider society, the ways in which friendships are formed and nurtured is changing with people recognising that they can develop deep, meaningful connections with others that they've never met, and may never meet," said Oxley.
The internet is particularly useful for those who are physically handicapped.
"People with illnesses often rely on the internet's ability to facilitate friendships as they blog and use networking sites as a way of coming to terms with, and dealing with their illness. It can foster a sense of social connection for those who can frequently feel isolated, which is important to psychological wellbeing."