digraph G {
 rankdir=TB
 node [shape=box, fontsize=9, height=0.1, width=0.05 ]
 edge [arrowsize=0.5, len=0.1]
"Diagnosis\n"->"Diagnose\nTreatment\n"
"Diagnose\nTreatment\n"->"Diagnose\n"
"Diagnose\nTreatment\n"->"Treatment\n"
"Diagnose\n"->"Treatment\n" [weight=2.0, color=blue]
}