In many ways, this reaction is the opposite of the sympathetic response, in that it slows the heart rate and can cause the patient to either regurgitate or temporarily lose consciousness. In this stress response, the body releases acetylcholine. This response is fairly often triggered by the sight of blood.

Parasympathetic acute stress disorder is characterised by feeling faint and nauseous. However, other physical illnesses become more difficult to diagnose, as ASD masks the pain and other vital signs that would otherwise be symptomatic. The 'fight or flight' response may allow for temporarily-enhanced physical output, even in the face of severe injury. This type of ASD developed as an evolutionary advantage to help humans survive dangerous situations. These hormones may speed up a person's pulse and respiratory rate, dilate pupils, or temporarily mask pain. Sympathetic acute stress disorder is caused by the release of excessive adrenaline and norepinephrine into the nervous system. It may bring about delayed stress reactions (better known as post-traumatic stress disorder, or PTSD) if not correctly addressed.

For the circulatory condition, see Shock (circulatory).ДЄcute stress disorder ( ASD, also known as acute stress reaction, psychological shock, mental shock, or simply shock) is a psychological response to a terrifying, traumatic or surprising experience. This article is about the psychological condition sometimes called shock.

Acute stress disorder dsm 5