Health: A state of physical, mental and social
well-being and not merely absence of a disease.
Disease: Departure from normal state of health
through structural or functional disorders of the body.
Communicable Diseases: Diseases that are caused by pathogens
and can be transmitted from an infected person to the other. Example:
Non-communicable Diseases: Diseases that are
caused by factors other than pathogens and are not transmitted from one
person to the other. Example: Arthritis.
Contagious Diseases: Diseases that spread through physical
contact with the infected person. Example: Scabies.
Hepatitis: Inflammatory condition of the liver.
Cancer: An uncontrolled and abnormal growth of
cells resulting into a tumor.
Carcinogen: Cancer-causing agent.
Leprosy: A chronic, infectious disease characterised by granulomatous
lesions of the skin and peripheral nervous system.
Metastasis: Transfer of disease from one part of the
body to the other either through transfer of pathogenic microorganisms or
through transfer of cells. For example, all malignant tumors can spread to
other parts of the body through blood or lymph and form secondary tumors.