A phobia is a persistent fear of a specific object or situation, which is out of proportion or excessive. This fear often causes individuals to avoid situations or suffer through them, as the situation or object will produce a high level of distress.
There are four sub-types of phobias:
Specific phobias can be caused by a distressing experience in the past which was either personally experienced or witnessed (e.g., being bitten by a dog in the case of someone with a dog phobia). Often phobias develop in childhood and persist into adult life, but can develop at any stage in an individual’s life.