Doctors came to see her singly and in consultation, talked much in French, German, and Latin, blamed one another, and prescribed a great variety of medicines for all the diseases known to them, but the simple idea never occurred to any of them that they could not know the disease Natasha was suffering from, as no disease suffered by a live man can be known, for every living person has his own peculiarities and always has his own peculiar, personal, novel, complicated disease, unknown to medicine.
- Leo Tolstoy
Other anxiety disorders include Anxiety Disorders due to a General Medical Condition (where the anxiety is a direct physiological consequence of a general medical condition), Substance-Induced Anxiety Disorder (where the anxiety is directly caused by the physiological effects of a substance - drug of abuse or medication - including prescription use, poisoning, intoxication, or withdrawal), and Anxiety Disorder Not Otherwise Specified (where there is prominent clinically significant anxiety or phobic avoidance that doesn't meet the diagnostic criteria for any other anxiety or adjustment disorder).
Health anxiety disorder and hypochondriasis are typically classified under Somatoform disorders.