NCERT Class 8 Science Chapter 3
Health: The Ultimate Treasure
NCERT Class 8 Science Chapter 3 explores the concept of health in its complete sense — physical, mental, and social well-being. This CBSE chapter discusses communicable and non-communicable diseases, their causes, prevention, and the importance of personal hygiene and a balanced diet. Students learn how lifestyle choices directly affect long-term health and quality of life.
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Key Terms
- Health
- A state of complete physical, mental, and social well-being, not merely the absence of disease, as defined by the World Health Organization (WHO).
- Communicable Disease
- A disease that can spread from one person to another through direct contact, air, water, food, or vectors (e.g., tuberculosis, cholera, dengue).
- Non-communicable Disease
- A disease that does not spread from person to person; usually caused by lifestyle factors or genetics (e.g., diabetes, cancer, heart disease).
- Pathogen
- A disease-causing microorganism such as bacteria, virus, fungus, or protozoa.
- Immunity
- The ability of the body to resist and fight off infections and diseases using the immune system.
- Personal Hygiene
- Practices that maintain cleanliness of the body to prevent the spread of diseases, such as hand washing, bathing, and oral care.
- Balanced Diet
- A diet that contains all essential nutrients — carbohydrates, proteins, fats, vitamins, minerals, and water — in the right proportions for good health.
Frequently Asked Questions
What is health Class 8 Science?▾
According to NCERT Class 8 Chapter 3, health is a state of complete physical, mental, and social well-being. Being healthy does not just mean the absence of disease — it also means having good mental health, positive relationships, and a balanced lifestyle.
What is the difference between communicable and non-communicable diseases Class 8?▾
Communicable diseases (like tuberculosis, cholera, and dengue) can spread from one person to another through pathogens. Non-communicable diseases (like diabetes and cancer) do not spread between people and are typically caused by genetics, unhealthy lifestyle, or environmental factors.
How can diseases be prevented Class 8?▾
Diseases can be prevented by maintaining personal hygiene (washing hands, clean drinking water), eating a balanced diet, exercising regularly, getting vaccinated, avoiding contact with sick individuals, and keeping the environment clean. NCERT Class 8 Chapter 3 covers these preventive measures.
What is a pathogen Class 8?▾
A pathogen is a microorganism that causes disease. Pathogens include bacteria (causing tuberculosis), viruses (causing dengue), fungi (causing ringworm), and protozoa (causing malaria). Understanding pathogens helps in preventing and treating diseases.
What are the components of health Class 8 CBSE?▾
Health has three main components: (1) Physical health — proper functioning of the body, (2) Mental health — emotional and psychological well-being, (3) Social health — ability to interact well with others. All three are equally important for overall well-being.
Why is a balanced diet important for health Class 8?▾
A balanced diet provides all the nutrients needed for the body to function properly — energy from carbohydrates and fats, growth and repair from proteins, regulation from vitamins and minerals, and hydration from water. Without a balanced diet, the body becomes weak and more vulnerable to disease.
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