Loneliness is or can be a (sometimes silent) killer. It is a complex and usually unpleasant emotional response to isolation or lack of companionship. You can be surrounded by millions of people and feel the utmost loneliness through lack of connection to other people. I hear London being called a lonely city all the time and that is one big place. It can be triggered by times of the year or it can be an ongoing issue highlighted by some event or something someone says or just there staring you in the face.