Social anxiety disorder (SAD), is an anxiety disorder characterised by a significant amount of social anxiety (fear in one or more social situations), causing considerable distress and impaired ability to function in at least some parts of daily life.  These fears can be triggered by perceived or actual scrutiny from others. Individuals with social anxiety disorder fear negative evaluation from other people.

Physical symptoms often include excessive blushing, excess sweating, trembling, palpitations, and nausea.  Stammering may be present, along with rapid speech. Panic attacks can also occur under intense fear and discomfort. Some sufferers may use alcohol or other drugs to reduce fears and inhibitions at social events. It is common for sufferers of social phobia to self-medicate in this fashion, especially if they are undiagnosed, untreated, or both; this can lead to alcoholism, eating disorders or other kinds of substance abuse. SAD is sometimes referred to as an illness of lost opportunities where “individuals make major life choices to accommodate their illness”.