Why Do We Fall Ill? Definition, Types, Examples & Uses

Why Do We Fall Ill?

Subject: General Science

Book: NCERT Science Class 9

Health is a state of complete physical, mental, and social well-being.
- **Types of Diseases**:
- Infectious diseases (caused by pathogens like bacteria, viruses).
- Non-infectious diseases (caused by lifestyle or genetic factors).
- **Prevention of Diseases**:
- Vaccination, hygiene, balanced diet.
- **Immunity**:
- The body’s defense mechanism against diseases.

**Possible Exam Questions:**
1. What is the difference between infectious and non-infectious diseases?
2. Explain how vaccines help prevent diseases.
3. How do bacteria and viruses cause diseases?
4. What is the role of immunity in disease prevention?
5. Discuss the impact of hygiene on public health.