A team of researchers from Swansea University and Milan University made a discovery that might lead you to question whether you should be spending so much time on social media.

The scientist were studying the effects of internet addiction on a group of volunteers and found that people who stay online for a long time go through a series of physiological changes when they finally get offline.

Among these physiological changes, which only occurred in volunteers who confessed to being internet addicts, the researchers list increased heart rate and elevated blood pressure.

What is more, these physiological symptoms, which were also mirrored by a surge in anxiety levels, seemed to be very similar to drug withdrawal.

These findings, published May 25 in the journal PLOS ONE, suggest that for some people, internet addiction is a real physical condition, which should be further investigated and perhaps even viewed as a disorder.

"We have known for some time that people who are over-dependent on digital devices report feelings of anxiety when they are stopped from using them, but now we can see that these psychological effects are accompanied by actual physiological changes," said study lead author Phil Reed, a psychology professor at Swansea University.

Internet Addiction And Its Withdrawal Symptoms

For the study, the team recruited 144 volunteers, with ages between 18 and 33, who had their heart rate and blood pressure measured before and after a brief internet session.

The researchers also evaluated participants' anxiety levels and self-reported internet addiction, described in the study as problematic internet use (PIU).

The experiment revealed that volunteers who were hooked on their digital devices experienced an average increase of 3 to 4 percent in heart rate and blood pressure — and, in some cases, even double the percentage — immediately after the internet session.

"Individuals who identified themselves as having PIU displayed increases in heart rate and systolic blood pressure, as well as reduced mood and increased state of anxiety, following cessation of internet session," the authors wrote in the abstract of their paper.

The team explains this increase, while not life-threatening, can be linked with feelings of anxiety, as well as changes in hormonal levels, that can ultimately diminish the immune response.

Furthermore, the combination of physiological changes and anxiety that kicks in when people with PIU stop using the internet resembles the state of withdrawal experienced with alcohol, cannabis, and heroin addiction.

According to Dr. Lisa Osborne, one of the study's coauthors, these physiological changes can make people feel even more anxious, particularly those with already high anxiety levels.

As a result, internet withdrawal fuels some people's need to reengage with their digital devices to get rid of these unpleasant feelings.

This study is the first controlled experiment to show the physiological changes resulting from internet exposure and continues the team's previous work, which focused on the psychological impact of excessive internet use.

The earlier research, conducted in 2013, showed internet addicts can suffer a form of cold turkey when they stop using the web.

Internet Users Go Online Mainly For Social Media

As part of the study, the volunteers were asked to state how much time they spend online every day and what they normally use the internet for.

According to their reports, the average time spent on the internet was 5 hours a day, with 13.9 percent of responders admitting to surfing the web for more than 9 hours daily.

Almost half of the volunteers (more than 40 percent) acknowledged they had an internet-related problem and mentioned they were aware of spending an excessive amount of time online.

The participants also indicated whether or not they had regularly visited particular types of websites in the past two months. The vast majority (91.6 percent) said they spent time on social networking sites, such as Facebook and Twitter.

Online shopping was also among the respondents' favorite activities, mentioned by 90.3 percent of the volunteers. Other frequent reasons for getting online were related to TV and film (69.4 percent), reading news (68.7 percent), dating (56.3 percent), content sharing such as posting on YouTube (45.1 percent), gambling and lottery sites (34.7 percent), and gaming (24.3 percent).

"The individuals in our study used the internet in a fairly typical way, so we are confident that many people who over-use the internet could be affected in the same way," said Reed.

"However, there are groups who use the internet in other ways, like gamers, perhaps to generate arousal, and the effects of stopping use on their physiology could be different — this is yet to be established," he added.