Panic attacks are intense periods of fear or feelings of doom developing over a very short time frame -- up to 10 minutes -- and associated with at least four of the following:

Sudden overwhelming fear
Palpitations
Sweating
Trembling
Shortness of breath
Sense of choking
Chest pain
Nausea
Dizziness
A feeling of being detached from the world (derealization)
Fear of dying
Numbness or tingling in the limbs or entire body
Chills or hot flushes

Panic attacks and panic disorder are not the same thing. All panic disorders have panic attacks as a symptom. But not all panic attacks are a component of panic disorder. There are other conditions that have panic attacks as a symptom. Some of those include:

Mitral valve prolapse
Hypoglycemia
Hyperthyroidism
Heart attacks
Social phobia
Agoraphobia

Generalized anxiety disorder is excessive and unrealistic worry over a period of at least six months associated with three of the following:

Restlessness
Easy fatigue
Difficulty concentrating
Irritability or explosive anger
Muscle tension
Sleep disturbances
Personality changes such as becoming less social

Phobic disorders are intense, persistent, and recurrent fear of certain objects (such as snakes, spiders, blood) or situations (such as heights, speaking in front of a group, public places). These exposures may trigger a panic attack. Social phobia and agoraphobia are examples of phobic disorders.

Posttraumatic stress disorder -- or PTSD -- describes anxiety (also known as post-traumatic stress disorder) caused by the exposure to either death or near-death circumstances such as fires, floods, earthquakes, shootings, assault, automobile accidents, or wars, for example. The traumatic event is re-experienced in thoughts and dreams. Common behaviors include the following:

Avoiding activities, places, or people associated with the triggering event
Difficulty concentrating
Difficulty sleeping
Being hypervigilant (you closely watch your surroundings)
Feeling a general sense of doom and gloom with diminished emotions such as loving feelings or aspirations for the future

Symptoms such as chest pain, shortness of breath, palpitations, dizziness, fainting, and weakness should not be automatically attributed to anxiety and require evaluation by a doctor.

WebMD Medical Reference

Reviewed by Amal Chakraburtty, MD on June 29, 2009