Which disorder is characterized by extreme fear and physical symptoms such as a racing heart?

Panic Disorder is characterized by sudden and recurrent panic attacks, which are intense periods of fear or discomfort that come on rapidly and can trigger physical symptoms. These symptoms often include a racing heart, shortness of breath, sweating, tremors, dizziness, and feelings of impending doom. Individuals experiencing a panic attack might fear losing control, having a heart attack, or dying. Unlike other anxiety disorders, panic disorder includes these discrete episodes along with persistent concern about experiencing more attacks or changes in behavior to avoid triggers.

In contrast, social phobia involves a fear of social situations where one may be scrutinized or embarrassed, and while it can have physical symptoms, they are more related to social interactions than sudden panic. Generalized Anxiety Disorder involves chronic anxiety and worry about various aspects of life but does not typically present with the acute episodes seen in panic disorder. Specific Phobia is focused on an irrational fear of a particular object or situation, which may induce fear responses, but again, it's more situational rather than the sudden and intense experience found in panic disorder.