Phobia is unreasonable fear. For example, some people are afraid of closed spaces, some of high places, some of lizards, some of spiders, etc. A person may become ‘phobic’ towards a situation after experiencing something shocking related to that situation. For example, he may have seen someone falling from a height and developed phobia related to height. Generally, one reacts to emotional pain by crying, breaking out in a sweat, etc. People who are more sensitive than others tend to develop phobia.