Why Do we Fall Ill Class 9 Extra Questions

CBSE Notes for Why Do We Fall Ill Class 9 Extra Questions 

Health is a state of physical, mental and social well-being. The health of the organism is determined by environmental factors. Environmental factors include social as well as physical factors. The word disease means “disturbed ease”. A symptom of a disease is a definite indication of the presence of a particular disease. Diseases are classified as acute or chronic, depending on their duration. Based on communicability, diseases are classified as infectious and non-infectious. Infectious agents spread through the air, water, physical contact or vectors. 

• Bacteria that cause tuberculosis, typhoid, anthrax, cholera, etc 

• Viruses that cause the common cold, influenza, dengue, AIDS, brain fever (Japanese encephalitis)

• Protozoans that cause kala-azar, malaria, etc 

• Worms that cause elephantiasis etc Causes of the disease can be immediate or contributory. 

A disease may be caused due to factors like: 

• Pathogens or infectious agents 

• Poor nourishment 

• Genetic abnormalities 

• Lack of public services Our immune system fights against the diseases. Activation of the immune system against infectious diseases results in inflammation and fever. Please refer Why Do We Fall Ill Class 9 Extra Questions for more information.