Do you often feel lonely? What do you do when you feel that way? Hide yourself away and spend your time reading, watching TV or walking around? You might think that feeling lonely is just like feeling happy, sad or scared -- that it's just one of your various moods. That is true. However, if you let yourself be lonely for too long without dealing with it, you could be making a serious mistake. Doctors have known for some time that feeling lonely is bad for the mind. It can lead to mental health problems such as depression, stress and reduce confidence. "Being lonely means not feeling connected or cared for, but it's not about being mentally alone," Lisa Jaremka, scientist from Ohio State University, US, told Live Science in January. And there's growing evidence that not having friends is connected with physical illness as well. In 2006, for example, scientists studied 2,800 women who had cancer. They found that those who had few friends or family were five times more likely to die of their disease than women with many social contacts. Also, even healthy people had a better chance of falling ill if they felt left out by others, according to the BBC. The results have scientists thinking that loneliness might hurt the immune system , which protects the body from diseases. Hoping to prove this theory, Jaremka and her research team put volunteers  through a stress test. During the test, volunteers were asked to make an unprepared speech in front of a group of stony-faced people. The researchers found that volunteers who said they were lonely in their daily lives felt more stress during the test. And their blood samples showed that all the stress had managed to cause harmful changes to their immune system. "Loneliness has been thought of in many ways as a chronic stressor  -- a socially painful situation that can last for quite a long time, " explained Jaremka, who led the study. The number of people suffering from loneliness is increasing all over the world. However, solving the problem is easier said than done. It won't work to just "tell anyone to go out and find someone to love you", said Jaremka. "We need to create support networks." We can conclude from the article that   _  .
loneliness has become the No. 1 killer in the world loneliness is increasing due to advanced technologies websites must be set up to help people deal with loneliness much more work needs to be done to fight loneliness