A phobia is a type of anxiety disorder, usually defined as a persistent fear of an object or situation the affected person will go to great lengths to avoid.Few Phobias.. Algophobia- Fear of pain.. Allodoxaphobia- Fear of opinions. Altophobia- Fear of heights. Amathophobia- Fear of dust. Amaxophobia- Fear of riding in a car. Ambulophobia- Fear of walking. Amnesiphobia- Fear of amnesia. Amychophobia- Fear of scratches or being scratched. Anablephobia- Fear of looking up.