Illness Anxiety Disorder (formerly Hypochondriasis)

Updated: Mar 06, 2018
  • Author: Debra Kahn, MD; Chief Editor: David Bienenfeld, MD  more...
  • Print


Hypochondriasis, which is now known as illness anxiety disorder, and the other somatic symptom disorders (e.g., factitious disorder, conversion disorder) are among the most difficult and most complex psychiatric disorders to treat in the general medical setting. On the basis of many new developments in this field, the DMS-5 has revised diagnostic criteria to facilitate clinical care and research. While illness anxiety disorder is included in the category of "somatic symptom and related disorders" it continues to have much overlap with obsessive-compulsive disorder and related illness.

As with all psychiatric disorders, illness anxiety disorder demands creative, rich biopsychosocial treatment planning by a team that includes primary care physicians, subspecialists, and mental health professionals.

This article describes illness anxiety disorder, its diagnosis, and an overview of treatment approaches, with references for details beyond the scope of the article. Finally, the article reviews new developments in psychopharmacologic and psychotherapeutic treatments.

Case study

A 45-year-old white male engineer presents to a primary care clinic armed with multiple internet searches on the topic of cancer. He states that he “just knows” he has a GI cancer, "probably the colon or maybe the pancreas." When asked how long this concern has bothered him he says "for years I have been concerned that I have cancer." You ask about relevant symptoms and he is a bit vague, saying "I get some pain or pressure right here (he points to the left upper quadrant) but it is not there all the time." Upon asking about prior workups he says “I have had ultrasounds and colonoscopies but they couldn't find anything. I was initially relieved but a couple of weeks later started to think that they must have just missed something.”

When you ask about the patient's goals for today’s visit he is emphatic. "I think what I really need is another colonoscopy and abdominal CT scan." His examination is unrevealing. When you suggest a less invasive approach, he brings up error rates of the other evaluations and shows literature endorsing how abdominal CT is the criterion standard. He is anxious at baseline and increasingly irritable when you propose less invasive evaluation. He ends the encounter by stating that he will “find another doctor who sees my point and will get me what I need.”



Neurochemical deficits associated with illness anxiety disorder appear similar to those of mood and anxiety disorders. For example, Hollander et al posited an "obsessive-compulsive spectrum" to include hypochondriasis, obsessive-compulsive disorder (OCD), body dysmorphic disorder (BDD), anorexia nervosa, and Tourette syndrome, all of which were believed to have similarities in responsiveness to serotonin reuptake inhibitors and to demonstrate "hyperactivity" in areas of the frontal lobes. [4]  A more recent article highlights the effectiveness of fluoxetine (a serotonin reuptake inhibitor and a mainstay in the treatment of OCD), as effective in the treatment of hypochondriasis. [2, 3]

While the formulation of obsessive-compulsive (OC) spectrum disorders has been adopted by the DSM-5, this new clustering does not include illness anxiety disorder. It does include: OCD, BDD, hoarding disorder, trichotillomania, excoriation disorder, OCD and other related disorders that are substance induced or due to another medical condition. In addition, encountering a patient with more than one of the anxiety spectrum disorders comorbid with illness anxiety disorder is not unusual. Findings of neurochemical deficits in patients with illness anxiety disorder are only preliminary, but such deficits may explain why symptoms overlap, why the disorders are commonly comorbid, and why effective treatments for OC spectrum disorders are also effective for illness anxiety disorder (eg, selective serotonin reuptake inhibitors [SSRIs]).

In a study of biological markers, subjects who met DSM-IV-TR diagnostic criteria for hypochondriasis had decreased plasma neurotrophin 3 (NT-3) levels and platelet serotonin (5-HT) levels, compared to healthy control subjects. NT-3 is a marker of neuronal function and platelet 5-HT is a surrogate marker for serotonergic activity. [6]




United States

Based on the previously defined "hypochondriasis," the DSM estimates that the community 1–2 year prevalence is 1.3–10%, while the 6-month to 1-year prevalence in medical outpatients is 3–8%. Some degree of preoccupation with disease is apparently common, because 10–20% of people who are healthy and 45% of people without a major psychiatric disorder have intermittent unfounded worries about illness. [7, 8]

International/cultural effects

Efforts have been made to quantify international rates of illness anxiety disorder and other somatic symptom disorders. Those rates are heavily influenced by the diagnostic criteria involved (ie, somatization disorder versus abridged somatization disorder) and how studies are conducted. [9] Within the US, researchers have also worked to define how culture and ethnicity interact to determine "idioms" of distress and also how these factors influence the physician-patient relationship. This research has included the formulation of patterns of presentations that can be classified as "culture bound syndromes." A selective literature review recommends that culture be considered in idiopathic somatic symptom presentations, but also that caution be taken to not be overly generalizing about ethnicity. [9]


Illness anxiety disorder is usually episodic, with symptoms that last from months to years and equally long quiescent periods. Although formal outcome studies have not been conducted, one third of patients with illness anxiety disorder are believed to eventually improve significantly. A good prognosis appears to be associated with high socioeconomic status, treatment-responsive anxiety or depression, the absence of a personality disorder, and the absence of a related nonpsychiatric medical condition. Most children are believed to recover by adolescence or early adulthood, but empiric studies have not been carried out.

Epidemiological studies are few, but patients with illness anxiety disorder appear to have no differences in age or gender than patients without this disorder. There have been several studies that have found patients with illness anxiety disorder to have decreased educational and income levels and higher rates of childhood illness and abuse. [7] These individuals use medical care at high rates, making frequent visits to the emergency department, the doctor, and other health care providers and undergoing frequent physical examinations, laboratory testing, and other costly, invasive, and potentially dangerous procedures. [10]

Cognitive, social learning, and psychodynamic theories imply that patients have significant psychosocial disturbances in terms of relationships, vocations, and other endeavors. Exacerbations may occur with psychological stressors and in patients with comorbid psychiatric conditions.

These high-use patterns differ dramatically from those of nonsomatizing patients and remain true even when comorbid medical conditions and sociodemographic differences are accounted for. [11] The medically unexplained complaint is often a symptom of illness anxiety [12] and may well be a presentation of associated abnormal illness behavior. [13]

Patients with illness anxiety disorder have a high rate of psychiatric comorbidity. [14] In one general medical outpatient clinic, 88% of patients with hypochondriasis had one or more concurrent psychiatric disorders, the most common being generalized anxiety disorder (71%), dysthymic disorder (45.2%), major depression (42.9%), somatization disorder (21.4%), and panic disorder (16.7%). These patients are 3 times more likely to have a personality disorder than the general population. [14] Substance abuse or dependence is also a serious comorbid condition, particularly use of benzodiazepines, though epidemiological studies have not assessed the exact frequency of this problem. The long-term prognosis of patients with hypochondriasis is understudied due to the heterogeneity of the disorder. However, higher severity at baseline is likely associated with worse outcome.

Sex- and age-related demographics

Illness anxiety disorder appears to occur equally in men and women.

The disorder can begin at any age, but the most common age of onset is early adulthood.