Fear of flying is most often an indirect combination of one or more other phobias related to air travel, such as claustrophobia (a fear of enclosed spaces), acrophobia (a fear of heights), or agoraphobia (especially the type that has to do with having a panic attack in a place you can’t escape from). Flight anxiety can also be linked to one’s feelings about the destination. It is a symptom rather than a disease, and different causes may spur anxiety in different individuals.