1.
CONCEPT
ON
HEALTH & DISEASE
Dr. Rajan Bikram Rayamajhi
Department of Community Medicine
B. P. Koirala Institute of Health Sciences
Dharan, Nepal 1

2.
Changing Concept
Biomedical Concept
It is based on Germ Theory of Disease .
[ Human body: a Machine , Disease: Breakdown of Machine ]
Limitation : minimized role of environment , psychology ,
social structure , culture in determining health.
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3.
Ecological Concept
Health is viewed as dynamic equilibrium
between human & environment .
(imperfect human versus imperfect environment)
It depends on human adaptability to natural
environment
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4.
Psychosocial Concept
Health is influenced by Social , Psychological ,
Cultural , Economic & Political factors.
Health is both biological and social phenomenon.
Holistic concept
It’s a unified or multidimensional and includes all
the concept.
It implies sound mind, in a sound body, in a sound
family, in sound environment.
It emphasis on the promotion and protection of
health.
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5.
Definition of Health
A state of complete physical, mental & social
wellbeing & not merely an absence of disease
or infirmity that enables an individual to lead
socially & economically productive life.
(WHO Definition of Health)
Infirmity – weakness/ illness over a long
period.
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6.
Definition of Health by WHO is Idealistic but
not Realistic.
Operational Definition:
Condition or Quality of the human organism
expressing the adequate functioning of the
organism in given conditions genetic or
environmental”
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7.
Health :
 No obvious evidence of disease. Person
functioning normally.
 Several organs functioning adequately in
equilibrium.
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8.
New Philosophy of Health
Fundamental Human Right , an essence of
productive life & an Integral part of
Development.
 Intersectoral
 Central to the concept of quality of life
Involves Individuals, State & International
Responsibility, a world-wide Social goal.
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9.
Dimensions of Health
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10.
Dimensions of Health
Physical Dimension
 Perfect functioning of body.
 Every cell / organ functioning at an optimum
capacity & in perfect harmony with rest of the
body.
Mental Dimension
A state of balance between the Individual and
surrounding world, Harmony between oneself and
others.
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11.
 Social Dimension
Quantity & Quality of an Individual’s
Interpersonal ties and extent of involvement with
Community , Degree of social functioning.
Spiritual Dimension
• Individual striving for meaning in Life , commitment
to some higher being.
• It also includes ethics, integrity, principles and
purposes in life.
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12.
Emotional Dimension
Refers to feeling.
Mental is related to knowing and cognition.
Vocational Dimension :
Work is fully adapted to human goals, capacities &
limitations, it often plays role in promoting health.
Goal achievement and self realization at work are a source of
satisfaction and enhanced self esteem.
Others: Philosophical, Cultural, Environmental,
Nutritional, Educational, Socio- Economic, Curative,
Preventive.
Various “non medical” dimensions have to be considered to
make an individual lead healthy life 12

13.
Positive Health
Perfect functioning of body and mind
[Depends also upon Economic, Cultural, Social factors operating in community]
Health is a Relative Concept
Positive health is a mirage as everything in life is
subject to change.
‘Dubos’: Concept of perfect positive health can’t come in reality
because man will never be so perfectly adapted to his
environment that his life will not involve struggles, failures and
sufferings. 13

14.
Concept of Well Being
It has objective and subjective components.
1) Standard of LivingStandard of Living [ WHO ]
1) Income : Per capita GNP 2) Occupation 3) Housing
Standard 4) Nutrition 5) Sanitation
6) Health 7) Education, 8) Recreation
Refers to the usual scale of our expenditure, the goods we consume and the services we enjoy.
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15.
2) Level of LivingLevel of Living [ UN ]
All of the above except Sanitation plus Clothing ,
Human Right & Social Security
Health impairment lowers level of living
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16.
3) Quality of Life :
A composite measure of physical, mental and social
wellbeing as perceived by each individual or group
of individuals.
For ex: Happiness /gratification experienced in life concerned with
health, marriage , family work, financial situation, educational
opportunities, self esteem, creativity, belongingness, trust in others.
Individual’s own subjective evaluation
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17.
Human Development Index (HDI)
A composite index combining indicators representing
3 dimensions
Longevity : life expectancy at birth
Knowledge: adult literacy rate and mean years of
schooling
Income
Income is only means to human development , not an end
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18.
Physical Quality of Life Index (PQLI)
1. Infant Mortality
2. Life Expectancy at age One
3. Literacy
Theme: Money is not everything
Oil rich countries of Middle East Asia have high per capita income
and Low PQLI
BUT
Sri Lanka , Kerala of India have low per capita income and high
PQLI 18

19.
Human Poverty Index: measures deprivation in 3 basic
dimensions
1) Probability of dying before 40 years
2) Adult Illiteracy Rate
3) Percentage of underweight children.
4) Percentage of population not using improved water source
Gender Empowerment Measure (GEM)
Gender related Development Index(GDI)
Kerala – High female literacy played key role in improving
health situation
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20.
Determinants of Health
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21.
Concept of Disease
oA condition where body or any of its part has its functions disrupted or
deranged.
( Oxford Dictionary)
oMal-adjustment of human organism to the environment. (Ecology)
oAny deviation from normal functioning(complete physical & mental
well being)
oIt has many shades (spectrum of disease) ranging from inapparent
(subclinical) cases to severe manifested illness
oFinal outcome of disease – Recovery , Disability, and Death.
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22.
Disease:Disease:
Physiological/Psychological
dysfunction; a condition that is
diagnosed by physician
 Illness:Illness:
Subjective state of the person who
feels aware of not being well.
 Sickness:Sickness:
State of social dysfunction, i.e., a
role that the individuals assumes
when ill (“sickness role”)
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23.
Concept of Causation
Before Louis Pasteur (1822 -1895 AD)
Supernatural theory of disease,
Theory of humor
Miasmatic theory – disease due to noxious air
Theory of spontaneous generation .
Discoveries of microbes:
(Germ theory of disease)
Gonococcus
Typhoid bacillus
Pneumococcus
Vibrio Cholera
Tubercle Bacillus
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24.
Epidemiological Triad
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25.
o Not everyone exposed to germs develop disease -
other factors relating to host & environment equally
important in determining whether disease will occur
or not
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26.
Agent Factors
o Biological agents:
Viruses, Bacteria, Protozoa
o Nutrient agents:
Proteins, Fats, Vitamins
o Physical agents:
Heats, Cold, Pressure
o Chemical agents:
Dust, Gases, Insecticides
o Mechanical agents:
Forces, Crushing, Tearing
o Absence or insufficiency or excess of a necessary to
health:
Hormones (Insulin) 26

27.
o Social agents:
Poverty, Smoking, Abuse of Drugs
o HOST Factors (Intrinsic)
o Demographic:
o : Age, Sex, Ethnicity
o Social & economic factors:
Income, Education, Occupation, Stress
o Lifestyle factors:
Living Habits, Physical Exercise, Smoking, Nutrition
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28.
Environmental Factors (Extrinsic)
• Physical environment: air, water, heat, noise,
climate, soil
• Biological environment: insects, rodents, dogs
• Psychosocial environment: culture, beliefs habits,
attitudes, education, health services
• Events like loss of close ones, loss of employment,
sudden exposure to stressful conditions anxiety,
depression, frustration - psychosomatic disorder
Duodenal ulcer, HTN, mental disorder
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29.
Disease/Health
Related Events
Risk factors
Heart Disease Smoking , High BP, Obesity , Lack of Exercise,
High Serum Cholesterol
Cancer Smoking, Alcohol, Radiation, Environmental
Pollution
Vehicle Accidents High Speed, Poor Road Quality, Vehicle Design,
Alcohol Use
Reference: Park’s textbook of Preventive & Social Medicine
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30.
Risk Factor
o For many disease “agent” unidentified example –
cancer , peptic ulcer , coronary heart disease.
o Etiology discussed in terms of Risk factors.
o Attribute/exposure significantly associated with
development of Disease.
o Some can be modified by intervention, reducing
the possibility of disease occurrence 30

31.
Web of Causation
oMulti factorial causation
Lung cancer : Genetic predisposition, Smoking
habit (No. of cig./day, Different forms of Tobacco) ,
Environmental Factors
Chronic disease: Outcome of Interaction of multiple
factors
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32.
Sometimes removal of just only one link/chain sufficient to control the disease
provided that the link is important
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33.
Natural history of disease :
The way in which a disease evolves over time from
earliest stage of its pre-pathogenesis phase to its
termination as recovery, disability or death, in
the absence of treatment or prevention.
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34.
Natural history of disease
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