Somatic Symptom and Related Disorders

Illness Anxiety Disorder


Author: Abdallah Aljabeiti
Scientific Editor: Ahda Jbarah
Linguistic Editor: Hala Qaryouti
Last Updated: 21/3/2021


Illness Anxiety Disorder (IAD) is a psychiatric disorder identified by excessive worry about having or developing a medical condition that is not yet diagnosed (1). This worry persists despite normal physical examination findings and lab results (2). People with IAD tend to pay excessive attention to normal bodily sensations (digestion, sweating, etc.), which they misinterpret as an indication of a worrisome disease (1). IAD falls under the wider category of “Somatic Symptom and Related Disorders” in the Diagnostic and Statistical Manual of Mental Disorders, 5th edition (DSM-5).


Brief History

IAD was previously called hypochondriasis, from the Greek work hypokhondria meaning ‘under the cartilage’, which refers to the area that the ancient Greeks thought to be the source of melancholy or worry (3). The name was changed in the DSM-5 due to the pejorative nature of this nomenclature (1).



Due to the novelty of IAD (as a diagnosis, not as a disease), the prevalence remains largely unknown. However, estimates can be extrapolated from the DSM-III and DSM-IV diagnosis of hypochondriasis (1,2,4). About 25% of patients previously diagnosed with hypochondriasis meet the criteria for IAD (1). The estimated prevalence of IAD is around 0.75% in the medical outpatient environment and around 0.1% in the general population (1,2). IAD has no gender predilection (1,4,5) and is more common in adolescents, unemployed individuals, and those who are less educated (1,5).


Etiology & Pathophysiology

Exact etiologies and how they come to cause IAD remain enigmatic. Nonetheless, the risk factors mentioned below can play a role in developing this disorder.


Risk Factors

Each of the following (alone or in combination) are risk factors thought to be implicated in the development of IAD:

  • Being raised in a family where health anxieties are frequently expressed, or if parents had disproportionate concerns about health-related issues (6).
  • Having personally had a serious illness in childhood, or having witnessed a serious medical condition in parent(s) or siblings (2,6).
  • Having a history of childhood abuse (4).
  • Having an underlying anxiety disorder (e.g. generalized anxiety disorder (GAD)) (1).
  • Having a first-degree relative with IAD (7).
  • Having a prior experience with the medical profession that resulted in diminished trust or confidence in physicians (7).
  • Spending an excessive amount of time reviewing health-related material on the internet (termed ‘Cyberchondria’) (1,8).


Clinical Presentation

As evident by the nature of the disease, IAD patients are more likely to be present in non-mental healthcare settings and are more likely to be in their early or middle adulthood. They usually present with the following:

  • Lack of or mild somatic symptoms (e.g. sweating or slight tachycardia).
  • Preoccupation with either the conviction of having or the fear of developing a serious illness ( e.g. the fear of memory loss in the elderly).
  • Disproportionate worry over the reality of the situation. (4)
  • Frequent monitoring for indicators of illness, such as checking blood pressure, pulse, temperature, or other physical changes several times a day and excessive body-checking (e.g. for skin lesions, hair loss, etc.) (1,4,8).
  • Being uncomfortable or intolerant when experiencing normal bodily sensations, and labeling them as pathological (1).
  • Excessive use of sources of information (e.g. the internet) for reviewing health-related concerns (1,8).
  • Having a history of multiple doctor visits with multiple doctors for the same problem (1,9).

Along with the aforementioned symptoms, most patients present within one of two categories (1,4):

  • Care-seeking type: these patients frequently utilize the health care system by regularly changing physicians and requesting multiple investigations/treatments.
  • Care-avoidant type: these patients avoid medical care. They have anxiety about presenting for diagnosis due to the belief that a life-threatening illness will be revealed.

Patients with IAD usually remain dissatisfied with any form of reassurance of negative physical exam findings or lab results. They also have a belief that their previous doctors were incompetent, in that they could have missed the correct diagnosis. (1,9)



The criteria for diagnosis by the Diagnostic and Statistical Manual of Mental Disorders, 5th edition (DSM-5) are as follows (4):

  1. Preoccupations involving having or developing a serious illness.
  2. Absence of somatic symptoms or, if present, they are only mild in intensity. In the presence of another medical condition or high risk for developing a medical condition (e.g., presence of strong family history), the preoccupation is clearly excessive or disproportionate.
  3. Having high levels of health anxiety, along with the individual being easily alarmed about his/her personal health status.
  4. Performing excessive health-related behaviors (e.g., repeatedly checking his/her body for signs of illness) or exhibiting maladaptive avoidance (e.g., avoiding medical care).
  5. Being preoccupied with the illness for at least 6 months, with the possibility that the specific illness that is feared may change over that period.
  6. The preoccupation is not better explained by another mental disorder, such as somatic symptom disorder, panic disorder, GAD, body dysmorphic disorder, obsessive-compulsive disorder, or delusional disorder (somatic type).

Specifiers include categorizing the patient as care-seeking or care-avoidant (4).

As mentioned above, having a medical condition does not preclude IAD diagnosis, since IAD can still be comorbid with medical illnesses, as long as the health-related anxieties or preoccupations are out of proportion to the objective reality of the medical illness (10).


Differential Diagnosis

The differential diagnoses for IAD include (4,10):

  • Other medical conditions: including neurological/endocrine conditions, occult malignancies, or other diseases affecting multiple body systems
  • Somatic symptom disorder (SSD)
  • Obsessive-compulsive disorder (OCD): the patient suffers intrusive thoughts of disease conviction or worry of developing a disease (obsessions) and might display compulsions, such as seeking reassurance
  • Anxiety disorders (e.g. GAD)
  • Adjustment disorders
  • Body dysmorphic disorder (BDD): considered as a differential because of the common display of repetitive body-checking habits.
  • Major depressive disorder: considered especially when the health-related anxieties mostly present in the setting of depressive episodes and disappear with the remission of the episodes
  • Psychotic disorders: considered especially when the somatic symptoms are of a delusional quality and an unrealistic nature (e.g. claiming that an organ is rotting or dead)
  • Personality disorders

One of the biggest challenges of diagnosing IAD is differentiating it from SSD because both conditions share a somewhat-similar presentation and are in fact sometimes falsely used interchangeably. The key to differentiating between them lies in identifying the predominant thought pattern. In IAD, patients are apprehensive of having or developing a disease whilst having  absent or minimal somatic symptoms.  In SSD, patients have one or more physical complaints not explained by a known medical condition. Another facet of differentiation is the nature of the symptoms experienced, wherein IAD they are of cognitive or emotional nature, and in SSD are somatic. (11,12)



Treatment revolves on three main axes: patient education, reassurance, and psychotherapy, all of which focus on helping IAD patients cope with their health anxieties. Pharmacotherapy can also be used but is not the mainstay of treatment. Most patients require a combination of pharmacotherapy and psychotherapy (10).

Only after medical illness has been ruled out should IAD be considered. Among the early stages of treatment, the care provider should be able to establish rapport with the patient so that the patient feels comfortable discussing their health concerns without feeling judged or dismissed with an invalidation of what they’re experiencing. The care provider should refer the patient to a psychiatrist (in a tactful and non-judgmental way) and schedule regular follow-ups with only one primary care provider to decrease the overutilization of medical systems and avoid unnecessary imaging studies, specialist referrals, and laboratory investigations. (1,2)

Of the psychotherapies used to manage IAD, cognitive behavioral therapy (CBT)  has received the most empirical support with many trials showing its efficacy (13). CBT emphasizes the role of dysfunctional maladaptive beliefs in maintaining the illness anxiety using behavioral modification strategies. It also may be useful in instructing patients on how to respond to bodily signals by educating them about normal somatic sensations and their normal variations. CBT may also address excessive body-checking habits (1,14).

Another form of psychotherapy often employed is mindfulness-based stress reduction (which results in enhanced psychological strength, decreased physical and psychological symptoms, increased ability to relax, and capacity to cope with long- and short-term stressors) (15) and exposure therapy (which teaches patients to confront the bodily sensations and situations avoided by a person due to fear of illness. It also teaches them to tolerate the uncertainty regarding a sensation being a real symptom or not and helps them recognize that the distress they experience is transient) (16).

Pharmacotherapy is used when the patient education, reassurance, and psychotherapy fail to adequately reduce the severity of the patient’s course of illness. Drugs used include antidepressants, namely SSRIs and SNRIs, which have been proven to be effective (2). Patients responding to antidepressant therapy are recommended to receive maintenance therapy for at least 6-12 months (10).



It is worth noting that IAD is a chronic disease that typically worsens with age (1,5). It adversely affects the patient’s personal life and relationships, as well as prevents normal functioning, and causes severe disability. Patients may frequently take leaves from work/school causing problems with their occupational functioning due to frequent fears of being sick. It also inflicts a financial burden from frequent healthcare visits and medical bills (4,9,17).

Some factors can worsen or improve the outcomes of IAD patients. Patients who are referred early for psychiatric evaluation have better outcomes as opposed to those who only receive general medical care. Other good prognostic factors include having a patient who is cooperative, tolerant, and hopeful. Patients who respond well to psychotherapy, pharmacotherapy or a combination of both have good outcomes. Reciprocally, patients with refractory IAD despite pharmacotherapy and psychotherapy have bad prognostic outcomes. (17)

IAD patients also have higher risks of developing a concurrent psychiatric illness such as other anxiety disorders, major depressive disorder, or personality disorders (4,10).


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1 Comment

  1. Thanks for the valuable information

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