Phobia:
a persistent, irrational fear of a specific object, activity, orsituation that leads to a compelling desire to avoid it.
A phobia is defined as an irrational, intense fear of an object or situation that poses little or no actual danger
I took my little sister to the doctor this week and she had to get her ears checked out.  She is exceptionally afraid of having things near or in her ears.  She doesn't fall under the scientific definition of a phobia, however she would under the typical view of society.  Phobia is a term often overused to define regular fears.  People use the word to describe regular fears like the fear of spiders or bugs.  

Phobias are only considered such if they get in the way of normal functioning and everyday life. However, fear in the traditional sense is a normal part of life.