A new study reveals that the more time one spent online, the more one increased the chances of catching a cold.
Scientists from Swansea and Milan Universities found that the immune system suffered damage from excessive use of internet.
They found that people who surfed the internet longer, were far more susceptible to catching the flu.
The study polled 500 people aged between 18 and 101 years.
Forty per cent of the participants who admitted to being mildly or significantly addicted to the internet had 30 per cent more cold and flu symptoms than those who spent less time online.
Researchers found that internet users suffered stress when they were disconnected from the web. The cycle of stress and relief caused levels of cortisol, a hormone affecting the immune function to fluctuate.
The daily Mail quoted Professor Phil Reed of Swansea University's College of Human and Health Sciences: "We found that the impact of the internet on people's health was independent of a range of other factors, like depression, sleep deprivation, and loneliness, which are associated with high levels of internet use and also with poor health."
''It may also be that those who spend a long time alone on the internet experience reduced immune function as a result of simply not having enough contact with others and their germs.''
The study found that on average people spent around six hours online daily, but some reported spending over 10 hours, most often connected with social media sites.
Men were more likely to access the internet for porn and gaming, while women tended to use it for social media and online shopping.
There were also differences in the way men and women spend their time online, women are more likely to use it for social media and shopping, whereas men are more likely to be gaming and watching pornography.