Slow Internet can seriously harm health, a group of Swedish scientists concluded, Life reports. 

Within the framework of a research project, the scientists asked 200 volunteers to watch a video on smartphones and tablets, meanwhile they measured their pulse, brain activeness and eye movement speed.  When the video loaded without delay, the condition of the test persons was neutral. But once the video hung for a few seconds, their heart rhythm significantly quickened.  

As it turned out, people feel emotional tension then as if they are under strong stress. According to the scientists, such anxiety strongly harms psyche and can even result in serious diseases.