1. Health and Disease
Health is a state of physical, mental, and social well-being. A disease is an
abnormal condition that negatively affects the structure or function of an organism.
2. Types of Diseases
- Acute vs Chronic: Acute diseases last for short periods (e.g., Cold);
Chronic diseases last for long periods (e.g., Tuberculosis).
- Infectious vs Non-infectious: Infectious diseases spread through
microbes (e.g., Malaria); Non-infectious diseases are internal (e.g., Cancer).
3. Infectious Agents
Include Bacteria, Viruses, Fungi, Protozoans, and Worms. They spread through air, water,
physical contact, or vectors (like mosquitoes).
4. Principles of Prevention
Prevention is better than cure. General ways include hygiene and public health measures.
Specific ways include Immunization (Vaccination) which primes the immune system to
fight specific pathogens.