Tuesday, November 1, 2011

The concepts of Illness and Disease

Note: These concepts, first published in 2011, have led to the book: Healthicine: The Arts and Sciences of Health and Healthiness which expands on them in detail.

As we live, and love, and work to understand and improve our health, we encounter illness and disease. We should take some time to understand the concepts and causes of illness and disease. What is disease, what causes illness?

It's always worthwhile to check the dictionary - and you can spend a lot of time checking different dictionaries and definitions.  I'll stick with Merriam-Webster.

Disease: trouble (obsolete); a condition of the living animal or plant or one of its part that impairs normal functioning and is typically manifested by distinguishing signs and symptoms; a harmful development (as in a social institution).

Illness: wickedness and unpleasantness (obsolete); an unhealthy condition of body and mind.

So, illness and disease can range from unhealthy bodily state, like a minor temporary dehydration caused by exercise, to a disease like cancer - which can kill an individual, to contagious disease that spreads through a population, to the diseases of crime and intolerance which can affect an entire society.  The word illness seems a bit more restrictive - but I'll use both interchangeably.

What is the cause of disease?

The generalized cause of all disease, is a deficiency or an excess. Although this might seem trivial, it is an important concept to the understanding of health and disease.

We can see in the image, that the defined transition from health to disease is very gradual.  The distinction moves very gradually from healthy to deficient, or from healthy to excessive. Of course a specific illnesses like a gunshot wound (excessive physical stress), can occur very quickly in time.
The specific cause determines the type and affects the severity of the disease.

A primary illness is one that has a single cause. A secondary illness is an illness that has two sequential causes, where the second cause is enabled by a primary illness. A complex illness is one that has more than one cause.

Another important distinction is the definition of a 'medical condition', which is diagnosed by a doctor based on  specific symptoms and signs.  A 'medical condition' is an illness or disease that passes a specific level of severity.  Note: Merriam-Webster does not define medical condition, an online search for medical condition takes you to the definition for disease. This a slightly different diagram shows the significance of a medical condition.
Note added Dec 30, 2011 "You can see in the above diagram that health includes, and is larger than illness."

To illustrate the variability of illness, you might have a gunshot wound through the tip of your fingernail - an insignificant illness for most of us, to a gunshot wound scraping the skin, requiring a band-aid, to a flesh wound, requiring a diagnosis and treatment by a physician, to a mortal wound. Each is an excess of physical stress, from minor to fatal. A medical condition does not formally exist until a physician makes a diagnosis.

In my blog, I often use the term 'wide grey' to define the gradual shading change seen as we gradually move from perfectly healthy to a serious state of deficiency or excess. I've deliberately used a gunshot wound to demonstrate the transition, and also to give an example of an illness that is very visible throughout the transition.  A medical condition is not a gray-scale.  It must be diagnosed, so there is a hard line where the existence of a medical condition is created by a physician.

It is unlikely that you would have the symptoms of a gunshot wound and not know the cause. There are many symptoms of illness where you do not know the cause.  And unless you are diagnosed by a physician, you might not know the name of the illness.

What is a symptom?  Merriam-Webster is a bit confusing on this definition: subjective evidence of disease or physical disturbance; broadly : something that indicates the presence of bodily disorder; a slight indication. I say it is confusing for two reasons.  Merriam-Webster's definition does not seem to recognize 'objective symptoms', which doctors generally seek for a more accurate diagnosis.  Also, it appears to restrict symptoms to indications of 'bodily disorders', thus excluding mental disorders, social disorders, etc. Although the third definition is vague and general enough to cover everything, perhaps even the symptom of dawn light as a symptom of the coming sunrise.

From the health point of view, a symptom is an indication that health is less than optimal.  Your health might be less than optimal - without symptoms.  However, once you experience, or someone, for example a doctor, detects something indicating that your health is less than optimal - that something is a symptom.

The hierarchy of health defines the layers and components of health from an overall view. Each component of health can range from perfectly healthy to deficient or excessive.

Many illnesses, in minor or severe states, have similar symptoms.  One of the most common symptoms is irritation or pain. It is important to remember that even the absence of pain can indicate an illness. Our sensations of irritation and pain can range from deficient to healthy to excessive.

As a result of the many hundreds, perhaps thousands of health components, and the overlapping of symptoms of illness, determining the cause of an illness is very complex.

Physicians can, and often do, diagnose the name of the illness, and prescribe treatment - without determining the cause.  Treatment, especially in an emergency situation, is more important than understanding the cause.

Identifying the cause is primarily useful for prevention of illness and disease.

What is the difference between healthiness and illness?

I view health as a natural state. And illness as an unnatural state.  And the transition, or wide grey area between health and illness as the way to measure health. It is important to measure health in order to study health scientifically.  Most of today's 'studies' of health are actually studies of illness - a powerful perspective to deal with illness, but a very weak perspective to understand health.

Perfect health is unattainable. The WHO (World Health Organization) definition of health is not useful to understand health, because it defines 'perfect health', saying "Health is a state of complete physical, mental and social well-being..."  This state cannot be attained.  Health must be measured. WHO spends lots of time and energy measuring illness - but health is not measured.  I believe this is partly because the WHO definition of health does not encompass the ability to measure health.

Because perfect health is unattainable - we can always measure the health of any health component, the health of an individual and even the health of a community.

Health is measured as between 100 (perfection) and zero (non-existent).  Health is the good stuff...

Illness is measured the other way. Illness is measured as zero (non-existent) to 100 (a confirmed diagnosis).  Illness is the bad stuff.

Are healthiness and illness opposites, or opposite ends of the same scale of life?  I don't look at it that way.  Our medical systems focus entirely on illness.  Only illness is measured, diagnosed and treated. Health is ignored, as if it only exists in perfection and as if nothing can be learned from studying health.

We should not confuse the good stuff (health) with the bad stuff (illness and disease).

I believe we must study health, separately from illness - to learn about health and improve our health.

That, in a nutshell, is the mission of this blog.  We need personal health freedom so that we can study health, learn about health, understand health better, and experience and improve our health as a result.

to your health,
Tracy is the author of two book about healthicine: 


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