concept of health

Health

Dr. Nisha Sangwan

Concept:“Health is a state of complete physical, mental and social

wellbeing and not merely an absence of disease or infirmity.”

now added “the ability to lead a socially and economically productive life.”

•The concept of health as defined by WHO is broad and positive in its implications; it sets out the standard, the standard of “positive” health.

CHANGING CONCEPTS OF HEALTH• Health is perceived in different ways giving rise to various concepts of health. Health has evolved over the centuries as a concept from an individual concern to a worldwide social goal.

Biomedical Concept• Health means “absence of disease.”• It was felt that human body is a machine and disease is an

outcome of the breakdown of the machine, and one of the doctor’s tasks was to repair the machine.

• Developments in medical and social sciences led to the conclusion that the biomedical concept of health was inadequate.

Ecological Concept•Ecologists viewed health as a dynamic equilibrium between man and his environment, and disease – a maladjustment of the human organism to environment.

– Health = is a dynamic equilibrium between man & his environment,

– Disease = maladjustment of the human organisms to the environment.

• The concept supports the need for clean air, safe water, ozonic layer in the atmosphere, etc. to protect us from exposure to unhealthy factors.

Psychosocial Concept•Advances in social sciences showed that health is not only a biomedical phenomenon, but one which is influenced by social, psychological, cultural, economic and political factors of the people concerned. Thus health is both a biological and social phenomenon.

Holistic Concept•Holistic concept recognizes the strength of social, economic, political and environmental influences on health. •It has been variously described as multidimensional process involving the wellbeing of the person as a whole •The emphasis is on the promotion and protection of health.

Health

Social economic

Envirnmental Political

Health promotion

Health protection

Holistic concept

DIMENSIONS OF HEALTH• Health is multidimensional and are interrelated, each has its own nature Physical Dimension• “Perfect functioning” of the body. • It conceptualizes health biologically as a state in which every cell and

every organ are functioning at optimum capacity and in perfect harmony with the rest of the body.

Mental Dimension• Ability to respond to many varied experiences of life with flexibility and a

sense of purpose.• Mental health has been defined as “a state of balance between the

individual and the surrounding world, a state of harmony between oneself and others

Social Dimension•Harmony and integration with the individual, between each individual and other members of society, and between individuals and the world in which they live.

“quantity and quality of an individual’s interpersonal ties and the extent of involvement with the community.”

Spiritual Dimension•Spiritual health refers to “something” that transcends physiology and psychology.

Emotional Dimension•Relates to “feeling.” it reflects emotional aspects of humanness.

Vocational Dimension•Work often plays a role in promoting both physical and mental health. •Physical work is usually associated with an improvement in physical capacity, while goal achievement and self-realization in work are a source of contentment and enhanced self-esteem.Others•A few other dimensions have also been suggested such as philosophical dimension, cultural dimension, socioeconomic dimension, environmental dimension, educational dimension, nutritional dimension, and so on.

CONCEPT OF WELLBEING

Standard of Living• As per WHO, “Income and occupation, standards of housing,

sanitation and nutrition, the level of provision of health, educational, recreational and other service and collectively as an index of the ‘standard of living’.”

Level of Living• As per United Nations documents “level of living” consists of nine

components: health, food consumption, education, occupation and working conditions, housing, social security, clothing, recreation and leisure, and human rights.

Quality of Life• Quality of life as defined by WHO, “The condition of life resulting from

combination of the effects of the complete range of factors such as those determining health, happiness , education, social and intellectual attainments, freedom of action, justice and freedom of expression.”

Physical Quality of Life Index• It includes three indicators such as

Infant mortalityLife expectancy at age oneLiteracy.

For each component, performance of individual countries is placed on a scale of 0 to 100,

Human Developmental Index•It includes

longevity (life expectancy at birth) knowledge (adult literacy rate) income (real GDP per capita)

The HDI value ranges from 0 to 1.

SPECTRUM OF HEALTH

• This concept of health emphasizes that health of an individual is a dynamic phenomenon and a process of continuous change, subject to repeated, fine variations

• Transition from optimum health to ill health is often gradual, and where one state ends and other begins is a matter of judgment.

• Different stages are positive health, better health, freedom from sickness, unrecognized sickness, mild sickness, severe sickness, and death.

Positive health

Better health

Freedom from sicknessUnrecognised sickness

Mild sickness

Severe sickness

Death

SPECTRUM OF HEALTH

DETERMINANTS OF HEALTH

Health

Biological

Gender Environment

Health services

Behavioral & sociocultural condition

Socioeconomic Aging

Other factor

Biological Determinants•Physical and mental traits of every human being are to some extent determined by the nature of his genes at the moment of conception.

Behavioral and Sociocultural Conditions•Health requires promotion of healthy lifestyle. Modern health problems especially in the developed countries and in developing countries are mainly due to changes in lifestyles. Healthy lifestyle includes adequate nutrition, enough sleep, sufficient physical activity etc.

Environment•Environment has a direct impact on the physical, mental and social wellbeing of those living in it.

• Environmental factors range from housing, water supply, psychosocial stress and family structure

Socioeconomic Conditions● Economic status: Economic situation in a country is an important factor in morbidity,

increasing life expectancy and improving quality of life, family size and pattern of disease

● Education: Illiteracy correlates with poverty, malnutrition, ill health, high infant and child mortality rates.

● Occupation: Productive work provides satisfaction, promotes health and improves quality of life.

● Political system: timely decisions concerning, resource allocation, choice of technology etc

Health Services•To be effective, the health services must reach the masses, equitably distributed, accessible at a cost the country and community can afford and social acceptable.Aging of the Population•A major concern of rapidly aging population is increased prevalence of chronic diseases and disabilities that deserve special attention.Gender•Women’s health is gaining importance in areas such as nutrition, health consequences of violence, aging, lifestyle related conditions and the occupational environment. •There is an increased awareness among policy makers of women’s health issues, and encourages their inclusion in all development as a priority.

INDICATORS OF HEALTH• Indicators should be valid, reliable and objective, sensitive, specific, feasible and

relevant.• The indicators are:1. Morbidity indicators2. Disability rates3. Nutritional status indicators4. Health care delivery indicators5. Utilization rates6. Indicators of social and mental health7. Environmental indicators8. Socioeconomic indicators9. Health policy indicators10. Indicators of quality of life11. Other indicators

Mortality Indicators•Mortality indicators represent the traditional measures of health status:● Crude death rate: It is defined as the number of deaths per 1000 population per year in a given community.

● Expectation of life: “the average number of years that will be lived” An increase in the expectation of life is regarded, inferentially, as an improvement in health status. It can be considered as a positive health indicator. It is a global health indicator.

● Infant mortality rate: It is the ratio of deaths under 1 year of age in a given year to the total number of live births in the same year; usually expressed as a rate per 1000 live births. It is one of the most universally accepted indicators of health status.

Child mortality rate: It is defined as the number of deaths at ages 1-4 years in a given year, per 1000 children. It is related to insufficient nutrition, low coverage by immunization, etc.

Under-5 proportionate mortality rate: It is the proportion of total deaths occurring in the under-5 age group. This rate can be used to reflect both infant and child mortality rates.

Maternal mortality rate: Maternal mortality accounts to the greatest proportion of deaths among women of reproductive age.

Disease-specific mortality rate: Mortality rates can be computed for specific diseases.

Morbidity Indicators•Morbidity indicators supplement mortality data to describe the health status of a population.

•Morbidity rates are incidence and prevalence, notification rates, attendance rates at outpatient departments, health centres, admission, readmission and discharge rates, duration of stay in hospital, and spells of sickness or absence from work or school etc.

Definitions of disease· Disease can be defined as a biosocial phenomenon characterized by interactions of pathological processes, defensive and adaptation processes resulting in damage of the organism as a whole, in limitation of the organism ability to adapt to living condition.

· Disease can be defined as a changes in individuals that cause their health parameters to fall outside the range of normal

· The term disease means a deviation from or an absence of the normal state

HEALTH AND ILLNESS

The Health-Sickness spectrum

EpidemiologyEpidemiology is the study of distribution and determinants of disease and conditions among populations.Disease distribution is considered in terms of Persons, time and place (Who, when and where). Persons who are affected by disease in terms of age, sex, race, occupation etc. The common characteristics relating to those persons affected by disease. Time relates to when the diseases is most likely to strike e.g. an epidemic, endemic, seasonal, cyclic etc Place refer to the geographical distribution of a diseases and the common characteristics that are favourable for that diseases in the given locality. Some diseases are localized, regional, pandemic etc.

Agent refers to the disease causing organism characteristics e.g. habitation, breeding migration, infectivity, climatic and environmental factors favouring its existence. Host refers to the biological makeup of the individuals that make the vulnerable to the specified illness e.g. physical condition, genetic make up, habits etc.Environment refers to the ecological conditions that favour the interaction of host and agent e.g. swampy areas, bushes within house holds, sanitation etc.

The natural history of disease consists of two phases:

1. Prepathogenesis - the process in the environment

2. Pathogenesis - the process in man

Natural History of Disease

Historical Theories for causation of disease

• “Supernatural causes”& Karma• Theory of humors (humor means fluid)• The miasmatic theory of disease• Theory of contagion• Germ theory• Epidemiological Triad• Multi-factorial causation• Web of causation

………Supernatural to multi-factorial causes…

Environment

Agent Host

Epidemiological triad Agent Factors

Physical Agents Chemical Agents Biological Agents Nutritional agents

Host FactorsSocio-demographic Factors Psycho-social Factors Intrinsic Characteristics

Environmental FactorsPhysical Environment Biological Environment Social Environment

The essential aspects of disease

1. disease is a new quality of life Health is a friedom, disease is a prison

2. disease is the result of one or more causes (noxas) and suitable conditions

3. disease is the unity of damaging, adaptive, defensive and compensation mechanisms

A picture of diseaase is created by: – pathologic reactions – pathologic processes – pathologic states

Pathologic reaction- It is the most simple, mainly short-lasting, quantitativly and/or qualitativly non-adequate response of organisms to some noxa

Examples: syncopa, short-lasting increase of BP, tachycardia, bradycardia, vomiting, diarhoe, hyperventilation ...

Pathologic process

It is the complex of pathologic and defensive-- adaptive reactions induced by influence of noxaon organism

Examples: inflammation, fever, hypoxia, growth of tumor, edema, acidosis, alkalosis...

Pathologic statePathological change which is stabile or it changes very slowly and in very small range during time period

Examples: congenital valvular heart disease, deafness, blindness, colour blindness...

Dynamics of diseaseDisease is a definite morbid process haveing a characteristic train of symptoms and signs

Dynamics of disease is characterized by stages of disease:

1st stage: latent – incubation (in infections diseases) Its duration is measured by time passed between beginning of noxa influence of body and beginning of first non-specific symptoms and signs of diseaseThere are no manifestations of disease during this stage

2nd stage: prodromal First non-specific symptoms and signs of disease arise

3rd stage: manifestation of disease

There are specific symptoms and signs characteristic for specific disease

4th stage: disease outcomes

a) healing and convalescence b) chronic disease c) death

Time course of disease

a) Peracute – onset during few seconds or minutesb) Acute – onset during hours and days, duration up to 3 weeksc) Subacute – duration up to 6 weeksd) Chronic – duration more than 6 weeks

Exacerbation of disease – usually sudden increse intensity of symptoms and signs of chronic diseaseRecidivation of disese – returning of previosly healed diseaseRemision of disease: decrese intensity of simptoms and signs of disease

ILLNESS AND DISEASE

· It is more important to know what sort of patient has a disease, than what sort of disease a patient has

· A person may "feel ill" without a disease being evident or diagnosed; likewise, a person may have a disease without experiencing any illness or suffering

· Illness tends to be used to refer to what is wrong with the patient, disease to what is wrong with his body

● Illness is what the patient suffers from, what troubles him, what be complains of, and what prompts him to seek medical attention

● When we say "a person is ill " we mean he feels uncomfortable, he is suffering from certain symptoms such as nausea, headache, abdominal cramps, or just fatigue that can't be explained on the basis of exertion● Disease refers to various structural disorders of the individuals tissues and organs that give rise to the signs of ill - health

· The principal factors accounting for nearly all diseases are:

1. heredity - inherited (genetic) diseases,

2. infectious organisms - infectious diseases, nosocomial disease3. lifestyle and personal habits - lifestyle diseases4. accidents

5. physical, chemical noxas (poisons and toxins)

COMMUNICABLE OR NON-COMMUNICABLE

HOW MUCH DO YOU KNOW ?

It is important to know whether a disease is Communicable (able to spread from one person to another), or Non-communicable (not transmissible from person to person).

In your book, copy down the listed diseases. Then place a (C) next to it if you think it’s Communicable or an (N) for Non-communicable.

*Extra credit: Tell what pathogen or life style factor is responsible for the disease listed.

ATHEROSCLEROSIS

INFLUENZA

ASTHMA

RINGWORM

POLIO

LUNG CANCER

HEART ATTACK

DIARRHEA

ATHEROSCLEROSIS

INFLUENZA

ASTHMA

RINGWORM

POLIO

LUNG CANCER

HEART ATTACK

DIARRHEA

N

C

N

C

C

N

N

C

Cholesterol

Virus

Allergy/stress

Fungus

Virus

Tobacco use

Diet, Heredity

Bacteria

EPILEPSY

KIDNEY STONES

SICKLE CELL

COLD

EMPHYSEMA

MEASLES

TUBERCULOSIS

A.I.D.S.

EPILEPSY

KIDNEY STONES

SICKLE CELL

COLD

EMPHYSEMA

MEASLES

TUBERCULOSIS

A.I.D.S.

N

N

N

C

N

C

C

C

Injury/congenital

Diet, water intake

Heredity

Virus

Tobacco use

Virus

Bacteria

Virus

Definition of Communicable diseases• A communicable disease is an illness due to a

specific infectious (biological) agent or its toxic products capable of being directly or indirectly transmitted from man to man, from animal to man, from animal to animal, or from the environment (through air, water, food, etc..) to man.

Common Pathogens: Viruses, Bacteria, Fungi & Protozoa

• Virus: smallest simplest life form. Not alive, and cause upper respiratory infections and many other type of diseases.

• Bacteria: simple one-celled organisms. They are everywhere. Not all bacteria is bad.

• Fungi: more complex than bacteria, but cannot make their own food. Thrive in warm, moist environments.

• Protozoa: one celled, animal like organisms.

Usually…• The poor hygiene behaviors promote the transmission of

infectious diseases

• The fecal-oral and respiratory routes are the most common sources of transmission

• Young children and adults may not wash their hands after using toilets and before eating/preparing food.

CD- Modes of transmission

• Direct• Blood-borne or sexual – HIV, Hepatitis B,C• Inhalation – Tuberculosis, influenza, anthrax• Food-borne – E.coli, Salmonella,• Contaminated water- Cholera, rotavirus, Hepatitis A

• Indirect • Vector-borne- malaria, trypanosomiasis• Fomites

• Zoonotic diseases – animal handling and feeding practices (Mad cow disease, Avian Influenza)

How are pathogens spread?• Direct Contact: hands and skin ex: Scabies• Indirect Contact: coughs, sneezes, expelling pathogens in the

air ex: flu• Contact with animals or insects – animal and insect bites ex:

Lyme’s disease (ticks) – chills, fever, headaches, discomfort, a skin eruption, and inflammation with swelling of the joints.

• Other contacts such as contaminated food or water. Ex: Salmonellosis – infection of the digestive tract. Sharp pain, fever, and bloody, watery diarrhea that occur 6 to 48 hours after eating. Nausea and vomiting are common.

Few Important Terminologies related to Communicable Diseases…-Infection

• Infection is the entry and development or multiplication of an infectious agent in the body of man or animals. An infection does not always cause illness.

• There are several levels of infection (Gradients of infection):– Colonization (S. aureus in skin and normal nasopharynx)– Subclinical or inapparent infection (polio)– Latent infection (virus of herpes simplex)– Manifest or clinical infection

Contagious disease

• A contagious disease is the one that is transmitted through contact. Examples include scabies, trachoma, STD and leprosy.

Vector of infection

• An insect or any living carrier that transports an infectious agent from an infected individual or its wastes to a susceptible individual or its food or immediate surroundings. Both biological and mechanical transmissions are encountered.

Epidemic

• “The unusual occurrence in a community of disease, specific health related behavior, or other health related events clearly in excess of expected occurrence”

• (epi= upon; demos= people)• Epidemics can occur upon endemic states too.

Endemic

• It refers to the constant presence of a disease or infectious agent within a given geographic area or population group. It is the usual or expected frequency of disease within a population.

• (En = in; demos = people)

Pandemic and Exotic• An epidemic usually affecting a large proportion of the

population, occuring over a wide geographic area such as a section of a nation, the entire nation, a continent or the world, e.g. Influenza pandemics.

• Exotic diseases are those which are imported into a country in which they do not otherwise occur, as for example, rabies in the UK.

Dynamics of disease Transmission (Chain of Infection)

Source or Reservoir Modes of transmission Susceptible host

I II III

(III): Susceptible host

• An infectious agent seeks a susceptible host aiming “successful parasitism”.

• Four stages are required for successful parasitism:1. Portal of entry2. Site of election inside the body3. Portal of exit4. Survival in external environment

Example :

• Agent (cold virus), leaves reservoir (throat of infected person), when host sneezes (portal of exit-nose and mouth). Direct transmission (saliva droplets) enter respiratory tract of susceptible host at close range (portal of entry-mouth). New infection possibly established. If one link is missing, chain is broken

Noncommunicable Diseases

• Nation’s leading causes of death– Heart disease, stroke, cancer

• Complex etiologies (causes)• Multicausation disease model– Host: inalterable, unique genetic endowment– Personality, beliefs, behavioral choices: impact

host– Complex environment: exposes host to risk factors

Multicausation Disease Model

Prioritizing Prevention and Control Efforts

• Criteria used to judge importance of disease to a community– Number of people who will die from a disease• Leading causes of death

– Number of years of potential life lost• Captures issues affiliated with various groups

– Economic costs associated with disease• Money spent at various levels of government; ex:

alcohol and other drugs

Prevention, Intervention, Control, and Eradication of Diseases

• Prevention: planning for and taking action to prevent or forestall onset of disease or health problem

• Intervention: effort to control disease in progress; taking action during an event• Control - Containment of a disease; prevention

and intervention measures• Eradication: total elimination of disease from

human population

Levels of Prevention

• Primary prevention– Forestall onset of illness or injury during

prepathogenesis period• Secondary prevention– Early diagnosis and prompt treatment before

disease becomes advanced and disability severe• Tertiary prevention– Aimed at rehabilitation following significant

pathogenesis; retrain, reeducate, rehabilitate

Primary Prevention of Communicable Diseases

• Strategies at each link in chain of infection– Individuals•Hand washing, using condoms, properly

cooking food–Communities• Chlorinating water supply, inspecting

restaurants, immunization programs for all citizens, vector control, solid waste disposal

• Individuals– Self-diagnosis, self-treatment w/home remedies– Antibiotics prescribed by a physician

• Communities– Controlling or limiting extent of an epidemic• Carefully maintaining records; investigating cases

• Isolation, quarantine, disinfection

Secondary Prevention of Communicable Diseases

• Individuals– Recovery to full health after infection; return to

normal activity• Communities– Preventing recurrence of epidemics• Removal, embalming, burial of dead• Reapplication of primary and secondary measures

Tertiary Prevention of Communicable Diseases

Primary Prevention of Noncommunicable Diseases

• Individuals– Education and knowledge about health and disease

prevention, eating properly, adequate exercise, driving safely

• Communities– Adequate food and energy supplies, efficient

community services, opportunities for education, employment, and housing

Secondary Prevention of Noncommunicable Diseases

• Individuals– Personal screenings (mammogram, pap test, PSA

test), regular medical and dental checkups, pursuit of diagnosis and prompt treatment

• Communities– Provision of mass screenings for chronic diseases,

case-finding measures, provision of adequate health personnel, equipment, and facilities

Tertiary Prevention of Noncommunicable Diseases

• Individuals– Significant behavioral or lifestyle changes,

adherence to prescribed medications, following rehabilitation requirements after surgery

• Communities– Adequate emergency medical personnel and

services: hospitals, surgeons, nurses, ambulance services

concept of health

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