Medical diagnosis is a complex function that requires the
combinatorial analysis of decision variables, most of which are
qualitative in nature. It is possible to group these variables and
arrange them in a hierarchical structure for the purpose of analysis.
There is a high level of uncertainty management medical
diagnosis.The act of medical diagnosis involves because human
reasoning and decision making is fuzzy, involving a high degree
of vagueness in evidence, concept utilization and mental model
formulation (Wang & Elhag, 2006).