Health and Hygiene

The One Thing

Good health is a state of physical, mental, and social well-being, maintained through healthy habits, adequate nutrition, hygiene, safe surroundings, and disease prevention. Preventing disease generally requires both individual responsibility and public health measures.

Reactions, Processes and Experiments

Key Terms

• Health: A condition of physical, mental, and social well-being that enables a person to live and work effectively.
• Hygiene: The set of practices that maintain cleanliness and protect health.
• Personal hygiene: Daily cleanliness practices such as bathing, washing hands, brushing teeth, wearing clean clothes, and keeping nails short.
• Public hygiene: Community measures that keep surroundings clean, including proper waste disposal, drainage, sanitation, and safe water supply.
• Disease: A condition in which the normal functioning of the body or mind is disturbed.
• Infectious disease: A disease caused by disease-producing organisms and capable of spreading from one person or source to another.
• Non-infectious disease: A disease that generally does not spread between people and may result from genetic, nutritional, lifestyle, or environmental factors.
• Pathogen: A disease-causing organism or agent, such as a bacterium, virus, fungus, protozoan, or parasitic worm.
• Communicable disease: An infectious disease that can be transmitted from an infected person, animal, or contaminated source to another person.
• Mode of transmission: The way a disease-causing agent spreads, such as through air, water, food, direct contact, vectors, or contaminated objects.
• Vector: An organism that carries and transmits a pathogen, such as a mosquito transmitting malaria-causing parasites.
• Immunity: The ability of the body to resist or fight infection.
• Vaccination: The process of giving a vaccine to stimulate the immune system to develop protection against a specific disease.
• Balanced diet: A diet containing carbohydrates, proteins, fats, vitamins, minerals, fibre, and water in suitable proportions.
• Sanitation: The safe management of human waste, wastewater, drinking water, and community cleanliness.
• Disinfection: The process of destroying or reducing harmful microorganisms on objects, surfaces, water, or skin.
• Quarantine: Separating people who may have been exposed to an infection to check whether they develop the disease.
• Isolation: Separating an infected person from healthy people to prevent disease transmission.

Easily Confused

• Infectious disease and non-infectious disease: An infectious disease is caused by disease-producing organisms and can spread from one person or source to another; a non-infectious disease generally does not spread between people.
• Infectious disease and communicable disease: A communicable disease is an infectious disease that can be transmitted from an infected person, animal, or contaminated source to another person.
• Immunity and vaccination: Immunity is the ability to resist or fight infection; vaccination is the process used to stimulate protection against a specific disease.
• Quarantine and isolation: Quarantine separates people who may have been exposed to infection; isolation separates an infected person from healthy people.
• Personal hygiene and public hygiene: Personal hygiene concerns an individual’s cleanliness; public hygiene concerns community measures such as sanitation, drainage, waste disposal, and safe water.
• Antibiotics and viral disease: Antibiotics act against certain bacterial infections but do not cure viral diseases.
• Malaria and dengue transmission: Malaria is transmitted by an infected female Anopheles mosquito, whereas dengue is commonly transmitted by infected Aedes mosquitoes.
• Carbohydrates and fats as energy sources: Carbohydrates provide approximately 4 kcal per gram, proteins 4 kcal per gram, and fats 9 kcal per gram.

What Gets Asked

• Define health and identify its three components. Marks are lost by describing health merely as the absence of disease rather than including physical, mental, and social well-being.
• Distinguish infectious, non-infectious, and communicable diseases. Marks are lost by treating all infectious diseases as necessarily transmitted directly between people or by omitting the role of contaminated sources.
• Identify modes of disease transmission and give examples. The required examples include common cold, influenza, and tuberculosis for airborne transmission; cholera, typhoid, and diarrhoea for water- and food-borne transmission; and malaria and dengue for vector-borne transmission.
• State measures for preventing disease. Answers should include personal hygiene, environmental sanitation, safe food and water, immunisation, vector control, early diagnosis, and appropriate treatment; omitting sanitation or safe water weakens the explanation.
• Explain the roles of diet and lifestyle in maintaining health. Marks are lost by excluding water and roughage from the discussion of essential dietary components, or by failing to mention exercise, sleep, relaxation, and avoidance of tobacco, alcohol, and harmful drugs.
• Calculate or interpret BMI and energy values. The required equation is BMI = body mass in kilograms divided by the square of height in metres; the energy values are carbohydrates 4 kcal per gram, proteins 4 kcal per gram, and fats 9 kcal per gram.