A phobia is an overwhelming and persistent fear of something. A phobia is an anxiety disorder, as it causes intense anxiety when the person is faced with the particular fear.
Some people do not experience anxiety until they come into contact with their phobia. However, others may experience anxious thoughts even when thinking about the phobia.
The cause of a phobia may be genetic, a learned response to a situation/object from someone close to you, or associated with a traumatic incident or situation relating to the specific fear. Phobias can also be caused by environmental factors. For example, I have anaphylaxis (a severe allergy) for which I carry epipens, I also have trypanophobia – fear of injections. I think my allergy is probably related to why I have this particular fear.
I have several posts on specific phobias, which I have listed below: