What is anxious vs anxiety disorder?

Normal vs. illness. "anxious" or anxiety is a normal, necessary human emotion. Anxiety disorders are abnormal conditions in which additional problems develop as a result of persistent, unnecessary anxiety. Doctors don't treat anxiety, per se. They treat anxiety disorders.
EmotionVsDiagnosis. Anxiety is a normal human emotion. It is like fear, but fear concerns what is right in front of you. Anxiety has to do with what 'might be' or 'might have been.' anxiety thus relates to worry and anticipation. An anxiety disorder is diagnosed when the anxiety focuses on a specific topic / stimulus (including initially unknown stimuli) and is severe enough to impair functioning.