Why are some people afraid of heights?

Some people have phobias or fears about something which are often irrational. It is a way of dealing with emotional stress or pain by associating it with a particular object or situation. Common phobias are fear of crowds or of small, enclosed places, of large wide-open spaces, of heights, and of some animals like cats, or insects like spiders, etc. People who have phobias don’t realize why they have it.