Panic disorder is characterized by recurrent, unexpected Panic Attacks which may be associated with persistent concern about having additional attacks, worry about the implications of the attack or its consequences (e.g., losing control, having a heart attack, "going crazy), or may be associated with a significant change in behavior related to the attacks.
A Panic Attack is a discrete period of intense fear or discomfort in which an individual experiences several of the following symptoms which develop abruptly and reach a peak within 10 minutes.
palpitations, pounding heart, or accelerated heart rate
sweating
trembling or shaking
sensations of shortness of breath or smothering
feeling of choking
chest pain or discomfort
nausea or abdominal distress
feeling dizzy, unsteady, lightheaded, or faint
derealization (feelings of unreality) or depersonalization (being detached from oneself)