Interestingly, physicians often diagnose and treat agoraphobia, like other phobias, when patients seek treatment for other medical or emotional problems rather than as the primary reason that care is sought. As with other mental disorders, there is no single, specific test for agoraphobia. The primary-care doctor or psychiatrist will take a careful history, perform or refer to another doctor for a physical examination, and order laboratory tests as needed. If someone has another medical condition that he or she knows about or there has been exposure to a medication, drug of abuse or other substance, there may be an overlap of signs and symptoms between the old and the new conditions. Just determining that anxiety does not have a physical cause does not immediately identify the ultimate cause. Often, determining the cause requires the involvement of a psychiatrist, clinical psychologist, and/or other mental-health professional.
In order to establish the diagnosis of agoraphobia, the professional will likely ask questions to ensure that the anxiety of the sufferer is truly the result of a fear of being in situations that make it impossible, difficult, or embarrassing to escape rather than in the context of another emotional problem (for example, fear of being near people that remind one of an abuser in the case of posttraumatic stress disorder or the fear of hearing voices that have no basis in reality as occurs in schizophrenia). The evaluator will also seek to determine if the symptoms of agoraphobia have occurred most times that the sufferer has been exposed to the previously described anxiety-provoking situations over at least a six-month period.