Social anxiety is the fear of social situations and the interaction with other people that can automatically bring on feelings of self-consciousness, judgment, evaluation, and inferiority.
Put another way, social anxiety is the fear and anxiety of being judged and evaluated negatively by other people, leading to feelings of inadequacy, embarrassment, humiliation, and depression. If a person usually becomes anxious in social situations, but seems fine when they are alone, then “social anxiety” may be the problem.
A specific social anxiety would be the fear of speaking in front of groups, whereas generalized social phobia indicates that the person is anxious, nervous, and uncomfortable in almost all social situations.
People with social anxiety disorder usually experience significant emotional distress in the following types of situations:
· Being introduced to other people
· Being teased or criticized
· Being the center of attention
· Being watched while doing something
· Meeting people in authority (“important people”)
· Most social encounters, especially with strangers
· Going around the room (or table) in a circle and having to say something
The physiological manifestations that accompany social anxiety may include intense fear, racing heart, turning red or blushing, excessive sweating, dry throat and mouth, trembling, swallowing with difficulty, and muscle twitches.
Constant, intense anxiety that does not go away is the most common feature.
People with social anxiety disorder know that their anxiety is irrational and does not make “head” sense. Nevertheless, “knowing” something is never the same thing as “believing” and “feeling” something. Thus, in people with social anxiety, thoughts and feelings of anxiety persist and show no signs of going away despite the fact that socially-anxious people “face their fears” every day of their lives.
Source: http://www.social-anxiety-network.com/define.html (abridged)