Why Do We Fall Ill Class 9 CBSE Notes - Chapter 13

Humans have been falling sick since times immemorial. Before science and technology, humans have attributed sickness to the supernatural, for instance, when there was a tuberculosis outbreak during the 19th century, people had associated its symptoms with vampirism. This is due to the fact that the patients often had very pale, deathly complexion and they would frequently cough up blood. But advancements in medicine and technology have provided a deeper insight into causative factors and the precautions one should take.

Health and Failure

Why Do We Fall Ill Class 9 Notes tells us that besides pathogenic causes, lifestyle practices also trigger various illness. A sedentary lifestyle increases the risk of heart diseases and certain metabolic disorders like diabetes etc.

Disease and Its Causes

There are many ways to classify diseases, for instance, it can be classified based on its communicability, the tissue or organ which is affected, pathogens, topographic, deficiency based, degenerative etc.

Why Do We Fall Ill Class 9 Notes – Questions

  1. What are the conditions required to maintain good health?
  2. What does being disease-free imply?
  3. What are infectious diseases?
  4. How do infectious diseases spread? List two examples.
  5. What is immunisation?

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Practise This Question

The farming technique where there is minimum or no use of chemical fertilizers, herbicides and insecticides is called ___.