Social anxiety disorder ( SAD ), also known as social phobia , is an anxiety disorder characterized by a significant amount of fear in one or more social situations , causing considerable distress and impaired ability to function in at least some parts of daily life.  :15 These fears can be triggered by perceived or actual scrutiny from others.
Social Anxiety is the third largest mental health care problem in the world today. Alcoholism is first, depression is second, and social anxiety is third. Social anxiety causes chronic anxiety and fear over social situations. It prevents people from leading the life they want; it stops them from taking the job they are good at doing; it prevents them from having friends and relationships, even though they want them. Social anxiety destroys lives. Yet it can be fully overcome with appropriate, active, structured, cognitive-behavioral therapy.
It can be easier to identify social anxiety within adults because they tend to shy away from any social situation and keep to themselves. Common adult forms of social anxiety include performance anxiety , public speaking anxiety , stage fright , and timidness . All of these may also assume clinical forms, i.e., become anxiety disorders (see below). 
We all know the feeling of being nervous or uncomfortable in a social situation. Maybe you’ve clammed up when meeting someone new or gotten sweaty palms before making a big presentation. Public speaking or walking into a roomful of strangers isn’t exactly thrilling for everybody, but most people can get through it.