Stress & Wellness Consulting • Occupational & Clinical Psychology
                    Panic disorder is an anxiety disorder characterized by recurring panic
                    attacks, causing a series of intense episodes of extreme anxiety during
                    panic attacks. It may also include significant behavioral changes
                    lasting at least a month and of ongoing worry about the implications or
                    concern about having other attacks. The latter are called anticipatory
                    attacks (DSM-IVR).
                    
                    Panic disorder is not the same as agoraphobia (fear of public places),
                    although many afflicted with panic disorder also suffer from
                    agoraphobia. Panic attacks cannot be predicted, therefore an individual
                    may become stressed, anxious or worried wondering when the next panic
                    attack will occur. Panic disorder may be differentiated as a medical
                    condition, or chemical imbalance. The DSM-IV-TR describes panic disorder
                    and anxiety differently. Whereas anxiety is preceded by chronic
                    stressors which build to reactions of moderate intensity that can last
                    for days, weeks or months, panic attacks are acute events triggered by a
                    sudden, out-of-the-blue cause: duration is short and symptoms are more
                    intense. Panic attacks can occur in children, as well as adults. Panic
                    in young people may be particularly distressing because children tend to
                    have less insight about what is happening, and parents are also likely
                    to experience distress when attacks occur.
                    
                    Screening tools like Patient Health Questionnaire can be used to detect
                    possible cases of the disorder, and suggest the need for a formal
                    diagnostic assessment.
                    
                    Panic disorder is a potentially disabling disorder, but can be
                    controlled and successfully treated. Because of the intense symptoms
                    that accompany panic disorder, it may be mistaken for a life-threatening
                    physical illness such as a heart attack. This misconception often
                    aggravates or triggers future attacks (some are called “anticipatory
                    attacks”). People frequently go to hospital emergency rooms on
                    experiencing a panic attack, and extensive medical tests may be
                    performed to rule out other conditions, thus creating further anxiety.
                    There are three types of panic attacks: unexpected, situationally
                    bounded, and situationally predisposed.
                
Source: https://en.wikipedia.org/wiki/Panic_disorder