Health is not merely the absence of disease. How can we define health? Classify diseases on the basis of:
$(i)$ Duration of the diseases:
$(ii)$ Cause of the diseases. Give one example of each type.

(N/A) Health is defined as a state of complete physical,mental,and social well-being,not merely the absence of disease or infirmity.
$(i)$ Classification based on duration:
$1.$ Acute diseases: Diseases that last for a very short period of time.
Example: Common cold.
$2.$ Chronic diseases: Diseases that last for a long time,even as much as a lifetime.
Example: Elephantiasis.
$(ii)$ Classification based on cause:
$1.$ Infectious (Communicable) diseases: Caused by external agents like pathogens (bacteria,viruses,fungi,protozoa).
Example: Malaria (caused by Plasmodium).
$2.$ Non-infectious (Non-communicable) diseases: Caused by internal factors like genetic abnormalities,hormonal imbalances,or nutritional deficiencies.
Example: Diabetes or Rickets (due to Vitamin $D$ deficiency).