Panic attacks:

are unexpected, isolated periods of intense anxiety, fear and distress that are associated with a range of somatic and cognitive symptoms. The onset of these episodes is usually sudden, and may have no apparent start. Although these episodes may appear accidental, they are considered to be a subset of an evolutionary comeback commonly referred to as fight or flight that happen out of context, flooding the body with hormones as particularly adrenalin, that aid in defending itself from harm.

The panic attack is different from other forms of anxiety by its concentration and its unexpected, episodic nature. Panic attacks are often experienced in conjunction with anxiety disorders and other psychological conditions, although panic attacks are not always pinpointing of a mental disorder, nor are they infrequent. Up to 10% of healthy people experience an isolated panic attack about once per year, and 1 in 60 people in the U.S.A. will suffer from a panic disorder at some point in their lifetime.

According to the American Psychological Association the symptoms of a panic attack frequently last about 10 minutes. However, panic attacks can be as short as 1-5 minutes, while more harsh panic attacks may form a cyclic series of episodes, lasting for an extended period. Often those afflicted will experience considerable anticipatory anxiety in between attacks and in situations where attacks have before occurred. Panic Attacks also affect people in a different way. Others, notably first time sufferers, may even call for emergency services; many who experience a panic attack for the first time fear they are having a heart attack. Experienced sufferers may be able to totally 'ride out' a panic attack with little to no clear symptoms.

Posttraumatic stress disorder (PTSD)
is the term for an acute and continuing emotional reaction to an excessive psychological trauma. The latter may involve someone's real death or a threat to the patient's or someone else's life, serious physical injury, or threat to physical and/or psychological uprightness. It is important to make a difference between PTSD and Traumatic stress, which is an alike condition, but of less intensity and length.

Hysteria was also related to "traumatic reminiscences" a century ago. At that time, Sigmund Freud's pupil, Kardiner, was the first to portray what later became known as symptoms of post-traumatic stress disorder. Stress is often defined as the reaction to a situation that threatens the balance or homeostasis of a system.

The situation causing the stress reaction is defined as the "stressor", but the stress reaction and not the stressor is what jeopardizes the homeostasis. Post-traumatic stress can thus be seen as a chemical inequality of neurotransmitters, according to stress theory.

However, PTSD in and of itself is a relatively recent diagnosis in psychiatric neology, first appearing in the Diagnostic and Statistical Manual of Mental Disorders. It has been said that development of the PTSD concept has, in part, socio-economic and political implications. War veterans are the most publicly-recognized victims of PTSD; long-term psychiatric illness was formally observed in World War I veterans. The syndrome entered wide public consciousness after the Vietnam War. PTSD patients had difficulties receiving veterans' disability benefits because there was no psychiatric diagnosis available by which veterans could claim indemnity.