According to the DSM-IV-TR, a Panic Attack is characterized by four or more of the following symptoms:
  1. palpitations, pounding heart, or accelerated heart rate
  2. sweating
  3. trembling or shaking
  4. sensations of shortness of breath or smothering
  5. feeling of choking
  6. chest pain or discomfort
  7. nausea or abdominal distress
  8. feeling dizzy, unsteady, lightheaded, or faint
  9. feelings of unreality (derealization) or being detached from oneself (depersonalization)
10.   fear of losing control or going crazy
11.    fear of dying
12.   numbness or tingling sensations (paresthesias)
13.   chills or hot flushes
Panic Disorder
The diagnostic criteria for Panic Disorder is defined in the DSM-IV-TR as follows:
Recurrent unexpected panic attacks and at least one of the attacks have been followed by 1 month (or more) of one (or more) of the above symptoms.  If the above criteria are met, the diagnosis is further clarified by the presence or absence of Agoraphobia or Panic Disorder without Agoraphobia).
It is important to know that the symptoms of panic disorder may mimic many other anxiety disorders and/or medical conditions. Only your doctor or mental health professional can diagnose panic disorder and panic attacks.