What is CLINICAL shock?

In medicine shock implies a failure by the circulation to meet the metabolic demand of the tissues. The failure of the circulation is usually, but not always, reflected by hypotension (low blood pressure).

Shock can result from loss of blood or severe fluid losses (hypovolaemia), loss of fluid from the circulating blood volume inside the body (distributive shock), weakness of the heart's contraction (cardiogenic shock) loss of the constrictive tone of the blood vessels (vasodilatory shock) and obstruction of the blood flow (obstructive shock). Often the cause of shock is a mix of more than one of these mechanisms.

Examples of specific causes of shock include: haemorrhage, burns, severe diarrhoea, anaphylaxsis, systemic infection, myocardial infraction, pulmonary embolism and cardiac tamponade.

Untreated persistent clinical shock will progress to multiple organ dysfunction and eventually death.

While anxiety, and psychological distress are symptoms of shock (caused by the activity of the sympathetic nervous system) the medical syndrome of clinical shock is quite distinct from the lay concepts of psychological shock perpetuated by the media.