A life-threatening condition where blood pressure is too low to sustain life. Occurs when a low blood volume (due to severe bleeding, excessive fluid loss or inadequate fluid uptake), inadequate pumping action of the heart or excessive dilation of the blood vessel walls ( vasodilation ) causes low blood pressure. This in turn results in inadequate blood supply to body cells, which can quickly die or be irreversibly damaged.

Anaphylactic Shock

The severest form of allergy which is a medical emergency. A Type I reaction according to the Gell And Coombs Classification . An often severe and sometimes fatal systemic reaction in a susceptible individual upon exposure to a specific antigen (such as wasp venom or penicillin ) following previous sensitization. Characterized especially by respiratory symptoms, fainting, itching, urticaria , swelling of the throat or other mucous membranes and a sudden decline in blood pressure.