Fears and phobias are the results of past incidents which the subject may or may not remember consciously. There is a subtle difference between fear and phobia. A fear is a natural reaction to perceived danger. Phobia is a much stronger reaction than fear to the perceived danger.
In any case both fear and phobia have some similarities as well. The reactions are basically same to the object of fear or phobia.
There are a lot of ways to deal with fears and phobias. Hypnotherapy and NLP are two most effective ways of dealing with them.
In therapy, we can either work with the symptoms and reprogram the mind to not react vigorously to the trigger of fear/phobia. We can also go back to the initial sensitizing event (first encounter that seeded the fear/phobia) and resolve the stuck emotions there.