It's normal to feel nervous in some social situations. Going on a date or giving a presentation may give you that feeling of having butterflies in your stomach, for instance. This isn't social anxiety disorder.
In social anxiety disorder, everyday interactions cause extreme fear and self-consciousness. It may become impossible for you to eat with acquaintances or write a cheque in public, let alone go to a party with lots of strangers. If your life is disrupted by this kind of fear, you may have social anxiety disorder.
If you or a loved one has social anxiety disorder, take heart. Effective treatment — often with cognitive behavioral therapy, medication and positive coping skills — can improve the symptoms of social anxiety disorder and open up new opportunities.