Several theories exist regarding what might cause agoraphobia. While the exact cause of agoraphobia is unknown, it is believed to stem from an interplay of biological, psychological, and environmental factors. For example, excessive introversion is associated with an increased likelihood of receiving an agoraphobia diagnosis. Individuals with avoidant, dependent, and anxious personality traits may also be more likely to develop agoraphobia.

Psychodynamic theory, a mental health theory focusing on how people respond to internal emotional conflicts, describes agoraphobia as a result of a feeling of emptiness stemming from an unresolved Oedipal conflict. While agoraphobia, like some mental disorders, is associated with a range of psychological and environmental risk factors, for some individuals it may arise due to a genetic component.