A loss of logical orientation, and often of memory as well, due to a lack of normal brain function caused by injury or age.
Example: You approach the elderly patient with your stethoscope and she withdraws in horror, yelling, “No more enemas! Get away!”
Grinnell, R. (2008). Confusion. Psych Central. Retrieved on August 4, 2015, from http://psychcentral.com/encyclopedia/2008/confusion/