Allergies: abnormal sensitive reactions of the immune system
- An allergy is an abnormal sensitivity or reaction of your immune system to a substance (an allergen) that you eat, inhale or touch. Non-allergic people can usually tolerate this substance.
- Nearly 50% of all people who suffer from allergies have hay fever.
- If both parents have allergies, their children are more likely to develop an allergy, although not always the same kind of allergy.
- Almost 70% of adults with food allergies are younger than 30 years and most children are under three years old.
The function of the immune system is to protect the body against foreign substances or hostile invaders such as viruses, bacteria and harmful chemicals. When such a substance enters the body, the immune system reacts by producing proteins called antibodies or by sending specific white blood cells called eosinophils to that area. Eosinophils attack infection, viruses, bacteria and other foreign substances. It is also these white blood cells that cause the immune system to overreact while they "attack" an invader, which usually is a substance harmless to other people. Antibodies against harmful substances are produced by beta-lymphocytes, the body’s white blood cells that are responsible for fighting infections. Antibodies attach themselves to the substances and set off a reaction that destroys them. Antibodies usually leave harmless read more
