1. the improper functioning of the body brought about by heredity, infection, diet, or the environment
disease
2. cannot be spread through contact or any mechanism of transmission
non - infectious disease
3. caused by the spread of harmful microorganisms
infectious disease
4. caused by the multiplication of a small infectious agent which invades a host cell and then destroys it
viral infection
5. caused by the reproduction of a small infectious agent which produces poisons that destroy cells
bacterial infection
6. caused by the multiplication of fungal organisms on or in the body
fungal infection
7. caused by microscopic parasites
protozoan infection
