"While we don't know exactly why or where phobias originate, they are a type of mental illness ... people suffer from the fear of the number 8, or octophobia, and the fear of 13, triskaidekaphobia ...

Specific phobias are out-of-proportion fears to objects, animals or situations, and fortunately, they can be treated.

To learn all about phobias, keep reading. We cover everything from the different types there are to what causes ... fear can affect our lives. Related: 8 Reasons You Could Be Afraid of Commitment ...