The actual sequence that leads to much chronic illness:
1) Among the body's systems is one of paramount importance, the autonomic nervous system, which controls many of the body's major functions automatically without any conscious input from you. In order to function correctly, part of which is body-healing and rebuilding, the autonomic nervous system needs to be supplied with real food - the true nutrients, proteins, carbohydrates, fats, enzymes, vitamins and minerals etc. provided by real whole foods and if these are not provided, the autonomic nervous system cannot do its job.
Chemically altered processed foods depleted of enzymes and fruits and vegetables grown in soils depleted of minerals do not provide the nourishment needed by the autonomic nervous system and they also give the body new unrecognized substances to deal with that can't be digested properly and that act as poisons in the body and weaken the organs and glands.2) People also get battered about by stresses from life (mostly from other people) and the strains and various toxicities of the environment, particularly prevalent in hair sprays, shampoos, facial and skin products for women, toxic mercury leaking out of fillings and root canals and the result is that their bodies, improperly nourished by fake foods, cannot properly respond to these stresses or even to correct nutritional treatments.
Certain well-known so-called "soft drinks" are highly toxic and shut down the liver and cause diabetes. Their "diet" counterparts are even worse and create symptoms that mirror the symptoms of MS, Lupus, Fybromyalgia and others. "Foods" radiated in microwaves become carcinogenic to the body. And people can also become allergic to or intolerant of everyday foods.
Enzyme deficiency, irritants such as alcohol and drugs, chemical preservatives, antibiotics, food allergies and toxins also create intestinal inflammation and contribute to the intestinal walls starting to leak those toxins and foodstuffs into the bloodstream. This leads not only to nutritional deficiencies but also to the body starting to attack itself and its own tissues and causes further allergies and all manner of unpleasant symptoms.
3) As the body starts to fall apart organ by organ the bacteria start moving in. They don't cause the problem, they come after the problem is caused. If you don't address the real problems, the body will not be able to repair the organs. Then people develop a "diagnosable disease".
4) Conventional "treatment" is to suppress the symptoms with more drugs or to use antibiotics to kill all the bacteria, bad and good, which create often worse symptoms.
5) Now the person is really sick. And the doctor doesn't know what's wrong with him but he can sure suppress the new symptoms and of course give him a whole new collection to deal with and so the vicious cycle continues and often leads to the by now over-toxic organ(s) being cut out of the body by surgery, which creates its own legion of problems. And thus we have people who eventually become medical wreckage with bodies so degenerated that their road back to real health can be a very long one indeed, if they even are able to fully recover, and sadly not all are.
Note: The above sequence applies equally to how a great many people, including an increasing number of children, are misdiagnosed and end up on psychiatric drugs, as the section on ADD on this site will cover in depth.