Definition of Panic attack

Panic attacks are sudden, discrete periods of intense anxiety, fear and discomfort that are associated with a variety of somatic and cognitive symptoms. The onset of these episodes is typically abrupt, and may have no obvious trigger. Although these episodes may appear random, they are considered to be a subset of an evolutionary response commonly referred to as fight or flight that occur out of context, flooding the body with hormones (particularly adrenalin) that aid in defending itself from harm.