Social anxiety is an intense feeling of fear, apprehension or worry regarding any or all social situations or public events. It is sometimes known as social phobia and, less commonly, social trauma. In psychiatry, it is diagnosed as social anxiety disorder, a form of anxiety disorder. It is currently the third largest mental health care problem in the world, according to United States epidemiological data.
Read more about Social Anxiety at Wikipedia.
Alternatively, this article from SocialPhobia.org discusses some of the forms of Social Anxiety,
More information :
This article by Dr Winston Bush is an excellent article on the causes of Social Phobia, explaining the structures of the brain responsible. It discusses Cognitive Behavioral Therapy (CBT) in some detail and explains why it is so effective in treating Social Anxiety. From that article :
Social phobia (also called social anxiety disorder) is an excessive fear of what other people might think of us. Our opinions of each other should matter — if they didn’t, we’d be living in a corner of hell, not a civilized society. But when someone is suffering from social phobia, he or she is feeling an exaggerated concern for public opinion — one that goes far beyond what we need in order to relate to other people for our mutual benefit.
Read the rest of what Dr Bush says here.