Health and Hygiene - Personal Hygiene and Cleanliness

Health is defined by the $WHO$ as a state of complete physical, mental, and social well-being and not merely the absence of disease or infirmity.

Hygiene refers to the science and practice of maintaining good health through cleanliness and proper care of the body.

Personal Hygiene involves individual practices such as regular bathing, brushing teeth twice a day, washing hands with soap ($C_{17}H_{35}COONa$), and trimming nails to prevent the growth of $Bacteria$ and $Fungi$.

Oral Hygiene is crucial to prevent dental carries and plaque; the enamel of teeth is made of $Ca_{10}(PO_4)_6(OH)_2$ (Hydroxyapatite), which can be eroded by acids produced by bacteria.

Cleanliness of surroundings (Community Hygiene) is essential to prevent the breeding of vectors like mosquitoes and houseflies that spread diseases.

Disinfectants like Bleaching powder ($CaOCl_2$) and Antiseptics like $Dettol$ are used to kill harmful microorganisms ($Pathogens$) on surfaces and skin.

The use of clean $H_2O$ (Water) for drinking and washing is the primary requirement for maintaining personal and domestic hygiene.