Health The Ultimate Treasure
Good health is one of our greatest treasures. This Class 8 Curiosity chapter explains what health really means, how a balanced diet keeps the body well, the diseases that arise from poor nutrition or from germs, and how cleanliness, immunity and vaccination help us stay healthy.
Learning objectives
- Explain health as physical, mental and social wellbeing.
- Describe a balanced diet and the main nutrients.
- Distinguish communicable and non-communicable diseases.
- List ways to prevent disease and stay healthy.
Key concepts
What is health?
Health is not just the absence of illness but a state of complete physical, mental and social wellbeing. A healthy person can work, learn and enjoy life. Good food, clean surroundings, exercise, rest and positive relationships all contribute to health.
Balanced diet and nutrients
A balanced diet provides the right amounts of all nutrients: carbohydrates and fats for energy, proteins for growth and repair, vitamins and minerals for protection and proper functioning, plus roughage (fibre) and water. Lacking a nutrient can cause a deficiency disease — for example, too little vitamin C causes scurvy and too little iron causes anaemia.
Communicable and non-communicable diseases
Communicable (infectious) diseases are caused by microbes and can spread from person to person — through air, water, food, or carriers like mosquitoes — examples being the common cold, tuberculosis and malaria. Non-communicable diseases do not spread between people and often relate to lifestyle or the body itself, such as diabetes and high blood pressure.
Prevention, immunity and hygiene
Many diseases can be prevented. The body's immune system defends against germs, and vaccination strengthens this defence against specific diseases. Washing hands, drinking safe water, eating clean food, keeping surroundings clean, exercising and getting enough sleep all reduce the chance of falling ill.
Key definitions
- Health
- A state of complete physical, mental and social wellbeing, not merely the absence of disease.
- Balanced diet
- A diet with the right amounts of all the nutrients the body needs.
- Communicable disease
- An infectious disease that can spread from one person to another.
- Immunity
- The body's ability to resist and fight disease-causing germs.
Solved examples
Q1. Which nutrient is the body's main source of energy?
Solution: Carbohydrates are the main energy source (fats also give energy).
Q2. Classify: (a) malaria, (b) diabetes.
Solution: (a) malaria — communicable (spread by mosquitoes); (b) diabetes — non-communicable.
Q3. How does vaccination protect us?
Solution: It trains the immune system to recognise and fight a specific germ before a real infection occurs.
Common mistakes to avoid
- Thinking health means only 'not being sick' — it includes mental and social wellbeing.
- Believing more food always means better nutrition; balance matters most.
- Calling lifestyle diseases like diabetes 'contagious' — they are non-communicable.
- Assuming clean-looking water is always safe to drink.
Health The Ultimate Treasure — MCQ Quiz
10 questions with instant feedback. Use number keys 1–4 to answer.
Health is best described as:
Practice questions
Short answer
Give one example each of a communicable and a non-communicable disease.
Communicable: malaria (or common cold). Non-communicable: diabetes (or high blood pressure).
Why is a balanced diet important?
It supplies all nutrients in the right amounts for energy, growth, repair and protection.
What is immunity?
The body's ability to resist and fight disease-causing germs.
Long answer
Describe the main nutrients in a balanced diet and one deficiency disease for two of them.
A balanced diet contains carbohydrates and fats for energy, proteins for growth and repair, vitamins and minerals for protection and proper body functioning, plus fibre and water. Deficiencies cause specific diseases: too little vitamin C causes scurvy (bleeding gums, weakness), and too little iron causes anaemia (tiredness, pale skin). Eating a variety of foods — grains, pulses, vegetables, fruits, milk — helps avoid such deficiencies.
Compare communicable and non-communicable diseases and explain how communicable ones can be prevented.
Communicable diseases are caused by microbes and spread from person to person through air, water, food or carriers such as mosquitoes; examples include the common cold, tuberculosis and malaria. Non-communicable diseases do not spread between people and are often linked to lifestyle or the body, such as diabetes and high blood pressure. Communicable diseases are prevented by hygiene (washing hands, clean food, safe water), keeping surroundings clean, controlling carriers like mosquitoes, and vaccination, which strengthens immunity against particular germs.
HOTS (Higher Order Thinking)
Two people eat the same amount of food, but one is better nourished. How is this possible?
Nourishment depends on balance, not just quantity; the better-nourished person eats a variety of foods supplying all nutrients, while the other may eat mostly one type and miss key nutrients.
Why does keeping surroundings clean reduce diseases like malaria and dengue?
Clean surroundings without stagnant water remove the breeding places of mosquitoes that carry these diseases, so fewer carriers means less spread.
Quick revision
Revision notes
- Health = physical + mental + social wellbeing.
- Balanced diet: carbohydrates, fats, proteins, vitamins, minerals, fibre, water.
- Deficiency diseases: vitamin C → scurvy; iron → anaemia.
- Communicable (spread by microbes) vs non-communicable; prevent by hygiene, safe water, vaccination.
Key takeaways
- Balance, not quantity, makes a diet healthy.
- Vaccination and hygiene prevent many communicable diseases.
- Lifestyle diseases do not spread from person to person.
Frequently asked questions
What is a balanced diet?
A diet that provides all the nutrients the body needs in the right amounts.
What is the difference between communicable and non-communicable diseases?
Communicable diseases spread between people; non-communicable ones do not.
How does vaccination help?
It trains the immune system to fight a specific disease before infection.