Yikes! My aunt had a stroke last month and now is experiencing some of the side affects mentioned. She's refusing blood work, blood pressure checks, etc, because she doesn't realize she's not OK. She feels fine, although the stroke affected her cognizant and speech skills. However, my dad, who had Parkinsons. suddenly became delusional and disorientated due to the side effects of so many medications.

Try to make notes of your dad's behavior to give to the doctor. I hope it's nothing serious and just a passing episode.