This document discusses concepts of health, disease, and their determinants. It defines health as a state of complete physical, mental, and social well-being according to the WHO. Physical health means normal body structure and functions, while mental health is a state of well-being and ability to cope with stress. Social well-being refers to ability to interact with others. Key determinants of health include heredity, environment, health services, and behaviors. Disease is defined as a physiological or psychological dysfunction, and natural history of disease describes its typical progression over time.

1. Prof. Saman Wimalasundera
MBBS . Do . PhD,
Professor in Community Medicine,
Former Head, Department of
Community Medicine,
Incharge Ophthalmologist,
Community Ophthalmology
Center,
Faculty of Medicine
University of Ruhuna
Sri Lanka

2. Concept of Health &
disease

3. Dimension and Determinants of
Health
Health is difficult to define but easier to
understand. To many of us it may mean
absence of disease or infirmity and to many
it may mean sound body and sound mind
and sound function of the body.

4. • To an anatomist
Healthy body means it should
confirm to normal anatomical
structures.
• To a physiologist
Health means normal
body functions

5. • To a biochemist
It means normal biochemical levels /
values
• To a pathologist
It means normal cellular make up.

6. • To a geneticist
It means correct existence of genetic
potential
Similarly to a clinician it means no
abnormality in structure and function of the
body. When a clinician fails to detect
anything abnormal by his clinical wisdom
and laboratory tests he labels a person
no abnormality detected (NAD).

7. • To a psychiatrist
It means well adjusted and a balanced
personality

8. Definition
“Health is a state of complete
physical, mental and social well being
and not merely the absence of disease
or infirmity”. WHO’s 191
member states have endorsed
this statement.

9. Physical Health
It means adequate body weight, height and
circumference as per age and sex with
acceptable level of vision, hearing, locomotion
or movements, acceptable levels of pulse rate,
blood pressure, respiratory rate,
chest circumference, head
circumference, waist hip ratio.

10. It means The body structure and functions
confirming to laid down standards within the
range of normal development and functions of
all the systems.

11. Mental health
The positive dimension of mental health is
stressed in WHO’s
definition of health as
contained in its
constitution.

12. Mental health is defined “as a state of
well being in which the individual realized
his or her own abilities, can cope with
normal stresses of life, can work
productively and fruitfully and is able to
make a contribution to his or her
community”.

13. A mentally normal person has the ability to
mix up with others, he/she makes friendship,
behaves in a balanced manner, keeps himself
tidy and observes adequate personal hygiene,
well oriented to time, place and person and
environments and he is unduly not suspicious of
others.

14. He is cheerful and happy and enjoys life
with a purpose and he thinks positively and
has normal development and contributes
fully and is useful and productive to society
and nation.

15. Social wellbeing
It is the third dimension of health. It
means ability of a person to adjust with
others in his social life, at home, at work
place and with people. Men interact with
men and they inter-relate and inter
depend on each other and pay their
effective role in accordance with a
situation.

16. Essentially social wellbeing includes
inter-relation and interaction of human
beings.
Social wellbeing is a composite
function of income level, literacy,
occupation and working conditions
marital harmony, institution of a family,
social groups and have good cultural and
behavioral patterns of the society.

17. Social wellbeing can be measured on
scale by taking in to consideration of
indicators like income, literacy and
occupation (as discussed under socio
economic status of family).

18. Determinants of health
Heredity
Health services
 Promotive,
preventive,
curative,
rehabilitative
Environment
 Physical, social,
biological and man-
made
Behavior
 Actions
 Habits
 Reactions
 Belief,
attitudes
 Practices
(Lifestyles)
Health

19. Environment
The environment is considered to be
the most important determinant and input
of health.

20. Man made environment
Health is influenced in the
man made environment or
artificial environment too.
It included items like
housing, transport,
industries and
communication.

21. Health services
Availability, accessibility, affordability
and acceptability of health services are
considered an important determinant /
input to health.

22. Health indicators
It is some what easier to defined
health for an individual. But to define
“community health” it is some what
more difficult. “Community health”
parameters are different from health
parameters of an individual.

23. “Community health” can be measured
through indicators of economics, (gross
national product gross national income and
per capita income), life expectancy, under
five mortality, infant mortality, literacy
level, composite index of human
development, maternal mortality etc.

24. A community is healthy when it enjoys
sound health where disease and death rate
is acceptably low, it is not threatened with
bad environments and its economy is sound
and the health resources are
available, practices are sound and
based on scientific evidences.

25. Its literacy levels are high and
demographically it has balanced sex
ratio and people live long, quality of
life is good and human development
index is high.

26. A village is said to be healthy if it has:
safe sources of improved water supply, safe
method of waste water disposal, paved
streets, disposal of garbage refuse and
animal excreta by manure pits, people use
sanitary latrines, female literacy is high,
girls enrolment is universal, deliveries are
conducted by trained persons, birth rate and
death rate are within acceptable limits,
immunization coverage is high and housing
condition is good.

27. Health is a fundamental human right.
The attainment of highest possible level
of health is the most important world
wide social goal.

28. The meaning of “Disease” is “without ease”
(uneasiness)
Either a Physiological /Psychological dysfunction
What is Disease

29. Not only presence of disease but involvement
of individual's perceptions and behavior in
response to disease are included. Disease is
very subjective.
Sickness
includes a state of social dysfunction too. i.e.
The role, an individual assumes when ill.
Illness

30. The environment related
to disease
This refers not only to the environment the man
lives. Various environmental factors are
categorized as follows.

31. 1. Physical Environment
Physical aspects of environment
Air, water, light, heat, radiation, gravity,
pressure, and chemical agents etc.
man tries a great deal to control these factors.

32. 2. Biological Environment
Certain diseases do not occur in some areas
because agents or vectors can not exist in that
environment due to biological reasons.

33. Biological environment
includes
Infectious agents of diseases, reservoirs of
infective agents, vectors that transmit
diseases, plants and animals.

34. 3. Social Environment
The social factors relevant to health include
socio-economic status, social customs,
traditional believes, etc.

35. Natural History of Disease
Refers to the course of a disease over a
period of time, unaffected by treatment.

36. Disease occurrence is usually insidious. Chronic
diseases evolve over a long period and have their
own progression. The history and time period that it
spread is different from disease to disease. Most
of the diseases pass through the
following pattern.

37. 1. Stage of susceptibility
Risk factors that favors the occurrence of a
disease are operating in this stage.
Host factors:- Age, sex, race,
family history, nutritional status
Environmental Exposure to infectious
factors:- agents, (infections) obesity, (HT,
DM, coronary artery diseases)
During this stage the person remains free of clinical
diseases

38. 2. Stage of pre-symptomatic
disease
Three important factors i.e.. Host, agent and
environment interact to initiate pathogenic changes
that is adequate to cause a disease.
Still the disease does not clinically manifest.

39. 3. Stage of clinical disease
In this stage, the particular signs and symptoms
develop. During this stage a disease can be sub
classified in to its own severity grades.

40. E.g. Cancers
Stage
I. Localized
II. Local Lymph nodes are involved
III. Involvement of other organs within the
same region
IV. Distant metastases

41. 4. Stage of terminations
Disease terminates and follow the following
trend
1. Spontaneous resolution –No sequels
2. Settles down but with some sequels.
3. Result in death of the patient.

42. 5. Stage of sequels
Disease may extinct but aftermath remains
may be an impairment is left.
Disability
Handicap

43. Disease Impairment Disability Handicap
Impairment
“Any loss or abnormality of psychological,
physiological or anatomical structure or function”.
e.g. Loss of foot, defective vision, mental retardation.
Sequence of events

44. Impairment will be
 visible or invisible
 temporary or permanent
 progressive or regressive

45. Disability
“Any restriction or lack of ability to perform an
activity in the manner or within or within the range
considered normal for a human being”.

46. Handicap
Definite disadvantages for a given individual
resulting from an impairment or a disability that
limits or prevents the fulfillment of a role that is
normal for him/her depending on his/her age,
sex, social and cultural factors or for that
individual.
e.g. Accident Disease
Loss of foot Impairment
Cannot walk Disability
Unemployed Handicap