⚡ Quick Revision: Health and Disease
Health is a state of complete physical, mental, and social well-being, and not merely the absence of disease.
Disease: Any condition that interferes with the normal structure or function of the body, characterized by specific symptoms.
Classification of Diseases
- ✔ Communicable (Infectious): Spread from an infected person to a healthy person (e.g., Common cold, Malaria).
- ✔ Non-Communicable: Do not spread through contact (e.g., Diabetes, Cancer, Scurvy).
⚡ Quick Revision: Pathogens & Communicable Diseases
Pathogens: Disease-causing microorganisms such as Bacteria, Viruses, Fungi, and Protozoa.
Common Pathogens and Diseases
| Pathogen | Diseases | Mode of Spread |
|---|---|---|
| Bacteria | Tuberculosis, Cholera, Typhoid | Contaminated food/water, Air. |
| Virus | Common Cold, AIDS, Polio | Direct contact, Air. |
| Protozoa | Malaria, Amoebic Dysentery | Vectors (Mosquitoes), Water. |
Modes of Transmission
- ✔ Direct Contact: Shaking hands or using an infected person's belongings.
- ✔ Air-borne: Droplets from sneezing or coughing (e.g., Influenza).
- ✔ Vectors: Animals that carry pathogens, like the Female Anopheles mosquito (Malaria).
⚡ Quick Revision: Non-Communicable & Deficiency Diseases
Deficiency diseases are caused by the lack of specific nutrients (vitamins or minerals) in the diet over a long period.
Common Deficiency Diseases
| Nutrient | Disease | Main Symptom |
|---|---|---|
| Vitamin A | Night Blindness | Poor vision in dim light. |
| Vitamin B1 | Beriberi | Weak muscles and very little energy. |
| Vitamin C | Scurvy | Bleeding gums, slow healing. |
| Vitamin D | Rickets | Soft and bent bones (bow legs). |
| Iron | Anaemia | Fatigue and pale skin. |
| Iodine | Goitre | Swelling in the neck region. |
Unlike infectious diseases, you cannot "catch" Scurvy or Rickets from someone else. They are strictly related to your own nutritional intake.
⚡ Quick Revision: Hygiene & Prevention
Hygiene: The practice of keeping oneself and one's surroundings clean in order to prevent illness and maintain good health.
Personal vs. Social Hygiene
- ✔ Personal Hygiene: Regular bathing, brushing teeth twice a day, washing hands before meals, and wearing clean clothes.
- ✔ Social Hygiene: Proper disposal of garbage, keeping water sources clean, and preventing stagnation of water (to stop mosquito breeding).
Methods of Prevention
1. Immunization (Vaccination): Developing immunity against specific diseases (e.g., BCG for TB, Polio drops).
2. Disinfection: Using chemicals like bleach or potassium permanganate to kill germs in water or on surfaces.
3. Sterilization: Boiling medical instruments or clothes to ensure they are free of microbes.
Proper handwashing with soap for at least 20 seconds is the single most effective way to prevent the spread of respiratory and digestive infections.