The number of diseases that makes up the medical lexicon is legion, but they can be broadly classified into two groups - interactional and intrinsic. 
 

Interactional maladies arise as a consequence of the unfavorable interaction between a human being and his or her environment - nutritive (excess or deficiency), microbial (worms, bacteria, viruses), mechanical or allergic. All the interactional diseases lend themselves to control (antibiotics in infections) or prevention (no allergens, no allergy; no cars, no car-accidents; no tubercle bacilli, no tuberculosis). Modern medicine’s golden - lettered triumphs have been in the field of interactional diseases - malnutrition mitigated, infections averted or treated, consequences of trauma minimized. 
 

Intrinsic diseases, as the appellation implies, are coursal ("course" with "al"-not causal), programmed in one way or another into a human being’s growth from the womb to the tomb, being the temporal signposts in the trajectory of an individual, and what is tellingly important, impervious to the march of modern medicine. The chief categories in this group are as follows:

• Birth defects: These diseases are a result of the defective formation and /or functioning of some parts of the body, that an individual is born with.

• Metabolic or Constitutional disorders: These result from an alteration in the functioning of the body systems and comprise such diseases as diabetes, high blood pressure, high acid secretion in stomach, autoimmune diseases, and so on. 

• Tumor /Cancer: Some cells in the body change their character, and by multiplication from cell colonies, called a tumor or cancer. 

• Vascular diseases : With age, arteries throughout the length and breadth of the body harden, narrow, and even get blocked. When such a process affects the artery to the heart or to the brain, heart attack or stroke may result. In pathological terms, such vascular changes are also called arteriosclerosis or atherosclerosis. 

• Collagenous disorders: The cells and the blood vessels of the human body are supported by a universal network of fibers made up of the protein, collagen. The progressive changes in collagen fibers produce wrinkling of the skin, stiffening of the joints, and contribute to the diseasing of the arteries mentioned above. 

Except for birth defects, all the other intrinsic disorders are an expression of the preprogrammed ageing of an individual. Hence it is independent of lifestyle

Few words on High Blood Pressure (HBP) and Diabetes

Both HBP and Diabetes are intrinsic in nature

• High blood pressure, medically called essential hypertension or essential high blood pressure, has remained as elusive entity for it has yet to be defined, satisfactorily for the doctor or rewardingly for the patient. Pickering, one time Regius professor of medicine at Oxford, showed that the ‘so-called essential hypertension’ is incapable of being defined except arbitrarily, the definition varying from day to day, doctor to doctor, and place to place. Doctors cannot decide whether or not what they call high blood pressure or hypertension is something natural to the patient, being ‘a disease in its own right;’ and no wonder, they hold the appellation essential, as essential to their hypertensive thinking. As is the definition, so too are the diagnosis, treatment, and prognosis of essential hypertension - arbitrary, erratic and anxiety-making. 

• Diabetes:  Boyd, an eminent pathologist and author, lamented that the more we know about it the less we seem to understand it. This continuing counter-productiveness stems from the fact that (a) diabetes - more completely called diabetes mellitus - has never been clearly defined, (b) the disturbance of glucose metabolism that doctors emphasize and treat represent only the tip of the iceberg of the disturbed metabolism of the patient, and (c) neither insulin nor any other ‘antidiabetic’ agent alters the course of the disease or the accompanying, inevitable arterial damage. It is chastising to note that 60 years after the epochal discovery of insulin and its (first) usage on Leonard Thompson, we know more about the inherent limitations of insulin therapy than about its presumed ability to ‘cure’ diabetes. 

(Interested viewers may like to read more from Living Dying by Dr. Manu Kothari and Dr. Lopa Mehta: Order your copy from Bhalani Medical Mumbai)