Social anxiety disorder, obsessive-compulsive disorder, and post-traumatic stress disorder are just a few of the many possible anxiety disorders. Although each anxiety disorder has its own distinct features, they all share a common theme of excessive, irrational fear and dread. Anxiety disorders are illnesses that cause overwhelming anxiety and fear that are chronic and unremitting, and that can grow progressively worse. If you think you may have an anxiety disorder, talk to your healthcare provider. Many different types of treatments are available, and these can be tailored to specific problems.