Concept of Health and Disease
The concept of health and disease is fundamental to all health-related disciplines, including pharmacy, medicine, nursing, and public health. In recent decades, our understanding of these concepts has expanded dramatically—from a narrow biomedical view to a much broader, multidimensional perspective. For pharmacy students and professionals, understanding these concepts is not only academic but also practical. A pharmacist is not just a drug dispenser, but also a healthcare provider, educator, counselor, and an integral part of public health systems.
This chapter delves deep into the definitions, interpretations, and evolving nature of health and disease, and explains how public health is evaluated and promoted for the betterment of society.
1. Understanding Health: A Multifaceted Concept
Health is not a simple or one-dimensional term. It is a dynamic, evolving, and multi-layered concept that incorporates physical, mental, social, and sometimes even spiritual aspects of human life. The modern view of health goes beyond simply being “not sick.”
1.1. Traditional View of Health
Traditionally, health was understood in biomedical terms—as the absence of disease or infirmity. If a person showed no symptoms of illness, he or she was considered healthy. This view dominated medical thought for centuries but was increasingly found inadequate, particularly with the rise of chronic illnesses, mental health issues, and psychosomatic disorders.
1.2. WHO Definition of Health
In 1948, the World Health Organization (WHO) introduced a revolutionary and holistic definition:
“Health is a state of complete physical, mental and social well-being and not merely the absence of disease or infirmity.”
This definition emphasized that health is not merely a biological phenomenon but involves the total well-being of an individual. It marked a paradigm shift in global healthcare perspectives.
Salient Features of WHO Definition:
- It is positive in approach, focusing on well-being rather than just pathology.
- It includes three essential components: physical, mental, and social well-being.
- It implies that health is a complete state, not a partial or fluctuating one.
However, this definition has also faced criticism, particularly for using the word “complete”, which implies a utopian and almost unattainable standard of health.
2. Dimensions of Health
To better understand the complexity of health, scholars have identified various dimensions of health. Each of these dimensions interacts with and influences the others:
2.1. Physical Health
Physical health refers to the proper functioning of the body. It includes:
- Freedom from disease and physical disability
- Ability to perform daily activities
- Normal growth and development
- Appropriate weight and nutrition
2.2. Mental Health
Mental health is the emotional and psychological well-being of an individual. A mentally healthy person can:
- Think clearly and logically
- Cope with daily stresses
- Maintain healthy relationships
- Adapt to change and adversity
Mental health issues are silent epidemics, often neglected but deeply impactful.
2.3. Social Health
Social health refers to the ability of a person to form satisfying interpersonal relationships and adapt comfortably to different social situations. It includes:
- Communication skills
- Social adaptability
- Supportive relationships
- Community participation
2.4. Spiritual Health (Optional Dimension)
Spiritual health refers to the inner sense of peace, purpose, and connection—either to a higher power, nature, or personal values. It influences decision-making, ethical behavior, and personal growth.
3. Concepts of Health: A Historical and Theoretical Overview
Over the years, different schools of thought have developed models or concepts of health, each focusing on certain key aspects of the human experience.
3.1. Biomedical Concept
The biomedical model views health in biological terms. According to this concept:
“Health is the absence of disease or dysfunction.”
It considers the body as a machine and disease as a breakdown of this machine. Diagnosis, treatment, and cure are the key goals of this model.
Limitations:
- Ignores psychosocial and environmental influences
- Suitable mainly for acute illnesses
- Lacks focus on prevention and health promotion
3.2. Ecological Concept
This model views health as a dynamic equilibrium between humans and their environment. Disease occurs when this balance is disturbed.
For example, when people live in areas with poor sanitation or polluted water, the risk of diseases like cholera, typhoid, or malaria increases.
This model encourages preventive approaches like sanitation, clean drinking water, vector control, and environmental safety.
3.3. Psychosocial Concept
This concept highlights the interaction between mind, body, and society. It proposes that health is influenced not just by biology or environment but also by:
- Emotional stress
- Lifestyle
- Cultural beliefs
- Economic status
This concept is particularly important for addressing mental health, substance abuse, and lifestyle-related diseases like hypertension and diabetes.
3.4. Holistic Concept
The holistic model is the most comprehensive. It integrates biomedical, environmental, mental, emotional, spiritual, and social factors. It emphasizes:
- Wellness rather than just absence of disease
- Balance and harmony in life
- Personal responsibility for health
Many alternative systems like Ayurveda, Yoga, and Naturopathy are based on this concept.
4. Understanding Disease: A Counterpart of Health
While health is a state of well-being, disease represents the disruption of that state.
4.1. Definition of Disease
A disease is:
“Any condition that impairs normal functioning of the body and is typically manifested by distinguishing signs and symptoms.”
It may be caused by pathogens, genetic mutations, nutritional deficiencies, toxic exposures, or behavioral factors.
4.2. Related Terms
| Term | Description |
| Illness | The personal, subjective experience of feeling unwell. |
| Disease | The objective abnormality identified by a healthcare provider. |
| Sickness | The social role and recognition of being ill in a community. |
These distinctions are important in pharmacy practice, especially when counseling patients who may perceive their illness differently from clinical assessment.
5. Evaluation of Public Health
Public health focuses on the health of populations rather than individuals. It involves the prevention of disease, prolongation of life, and promotion of health through organized efforts of society.
5.1. Definition of Public Health
According to Charles Winslow (1920):
“Public Health is the science and art of preventing disease, prolonging life, and promoting health through organized efforts and informed choices of society, organizations, communities, and individuals.”
5.2. Core Functions of Public Health
- Assessment – Monitoring health status and diagnosing health problems.
- Policy Development – Formulating public policies to improve health.
- Assurance – Ensuring access to effective health services.
6. Evaluation Methods in Public Health
To evaluate the effectiveness of public health systems, we use various tools, indicators, and strategies.
6.1. Health Indicators
These are measurable variables that reflect the health status of a population.
A. Mortality Indicators:
- Crude death rate
- Infant mortality rate
- Maternal mortality rate
- Life expectancy
B. Morbidity Indicators:
- Incidence and prevalence of diseases
- Hospital admission rates
C. Nutritional Indicators:
- Rate of underweight and stunted children
- Body Mass Index (BMI) distribution
D. Healthcare Delivery Indicators:
- Number of physicians and nurses per population
- Immunization coverage
- Access to essential medicines
E. Socioeconomic Indicators:
- Literacy rate
- Per capita income
- Access to clean water and sanitation
6.2. Methods of Evaluation
- Population Surveys (e.g., National Family Health Survey)
- Epidemiological Studies (e.g., cohort and case-control studies)
- Health Information Systems (HMIS, IDSP)
- Program Audits and Feedback Mechanisms
Conclusion
The concept of health and disease has shifted from a narrow, biological perspective to a broad, holistic understanding that includes physical, mental, social, and environmental dimensions. For pharmacy students and professionals, recognizing this comprehensive view is critical. It enables us to promote health, prevent disease, and evaluate public health systems with greater insight.
Understanding public health evaluation tools further helps pharmacists play an active role in community health promotion, disease surveillance, patient education, and rational drug use.