In the present study, the prevalence of anxiety disorders in patients with chronic diseases and the factors influencing it have been investigated. The prevalence of anxiety disorders is higher than other psychiatric disorders. 7.3% prevalence of this disorder in the United States of America has been higher than ever before. Its lifetime prevalence also reaches 14.6%. Almost all anxiety disorders are more prevalent among women and lower economic and social groups. Anxiety disorders are one of the most common classes of mental disorders. At the same time, in the national study of the United States of America, it has been reported that one out of every 4 people meets the diagnostic criteria of anxiety disorder and the 12-month prevalence of these disorders is 17.7%. Women are more likely to have an anxiety disorder with a lifetime prevalence of 19.2%. In order to determine the extent of the many aspects of anxiety, surveys of the general population indicate that more than one-third of adults suffer from a nervous disorder, especially anxiety. Regarding anxiety, by reviewing 22 studies conducted in this field, Max and Leader have estimated that approximately 3% of the general population suffers from anxiety. Cooper in 1969 reports that 27% of patients who present to their general practitioners with psychiatric symptoms are in a state of anxiety. 13% of children between 9 and 17 years old have anxiety. This classification includes a set of diseases such as obsession and fear of being in public.