A perfectly balanced immune system is elegant and economical. You recognize each threat accurately and with complete confidence, and only defend yourself just vigorously enough to neutralize it. There is the same poise and grace about this as you expect in the movements of a dancer.
In theory, this system could go out of balance either way — too little immune effort or too much. Too little is a disaster: diseases of weak immunity like AIDS are serious threats to life. Too much immune effort is a nuisance and can be very incapacitating, but at least your survival is not usually in question. So in almost all the chronic disease that can arise in your immune system, it is working too hard, exaggerating the effort it puts into overcoming a challenge.
Consequently the commonest symptoms are exaggerations too, caricatures of the normal defensive reactions at key entry points to your body — rhinitis and asthma, vomiting and diarrhoea, colitis, and eczema.
Once the challenge gets into your blood, new possibilities arise — rheumatism, migraine and headaches, and hyperactivity or other disturbances of mood and behaviour. The struggle to get it out of you again may challenge your liver and kidneys and the original disturbances in your lungs, nose and skin may be reinforced — they react just the same to irritants, whether these are in your breath or in your blood.
You may have inherited this problem, and have several near relatives who are affected as well. If so your blood contains large amounts of antibody, and challenge tests of various kinds produce strongly positive results. This condition is called atopy - a pronounced general allergic tendency. Atopic people are uncommon, and seem to possess a bodily defect which makes you unable to cope with a few perfectly natural allergens.
Atopy does not account well for a new wave of sensitivity problems that were first recognized in the middle of this century. At first these appeared to be allergies in the traditional sense. However challenge tests gave variable results that were hard to reproduce, and were seldom corroborated by positive skin or blood tests. The lists of allergens were so long and unreliable that most doctors threw out the whole idea: some even began to doubt that people affected like this should be taken seriously.
The explanation for this inconsistency is simple. Your immune system is not defective as in true allergy, but simply overwhelmed by stress. There are thousands more unnatural and irritant chemicals in our environment than there used to be, with current additions running at around ten every week. These heap increasing challenges on your immune system, so that it fails as your health declines. The problem in this case is not in you, but your surroundings.
The distinction is simple. If your immune system over-reacts abnormally to natural surroundings, you are allergic. If you are normal but over-react to unnatural challenges, you are intolerant.
Intolerance of this kind is now rapidly becoming very common in all developed countries. Government medical advisers still hugely underestimate it because they rely on a science that is out of touch. Your experience is all you need to convince yourself, however. And you do not have to put up with it.
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