Health encyclopaedia - Alphabetical Topic List

| A | | B | | C | | D | | E | | F | | G | | H | | I | | J | | K | | L | | M |
| N | | O | | P | | Q | | R | | S | | T | | U | | V | | W | | X | | Y |

Causes of Anaphylaxis

Anaphylactic shock occurs because the body's immune system over-reacts in response to the presence of a foreign body. Entry of the allergen into the blood stream provokes the release of massive amounts of histamine and other chemicals. The blood vessels widen, leading to a sudden severe lowering of blood pressure and constriction of the airways in the lungs.