Diagnosis of Illness Anxiety Disorder
Illness anxiety disorder (IAD) is diagnosed when a patient has persistent preoccupation with having or acquiring a serious illness for at least 6 months, with absent or minimal somatic symptoms, excessive health-related behaviors (such as repeated medical visits or avoidance), and clinically significant distress—all despite appropriate medical evaluation showing no serious illness. 1, 2
Core Diagnostic Criteria
The diagnosis requires all of the following elements to be present:
- Preoccupation with having or acquiring a serious illness that persists despite appropriate medical evaluation and reassurance 1, 2
- Somatic symptoms are absent or, if present, are only mild in intensity—this distinguishes IAD from Somatic Symptom Disorder where physical symptoms are prominent 1, 2
- High level of anxiety about health that is disproportionate to any actual medical risk 2, 3
- Excessive health-related behaviors such as repeatedly checking one's body for signs of illness, seeking reassurance from multiple physicians, or excessive medical visits; alternatively, some patients exhibit maladaptive avoidance of medical care 1, 2
- Duration of at least 6 months, though the specific illness feared may change over this period 2, 3
- Clinically significant distress or impairment in social, occupational, or other important areas of functioning 2, 3
Key Distinguishing Features
The central feature that separates IAD from other anxiety disorders is the cycle of worry and reassurance-seeking specifically about health, rather than generalized worry about multiple life domains (as in GAD) or distress from prominent physical symptoms (as in Somatic Symptom Disorder) 2. Patients remain unsatisfied with physician reassurances because their distress stems from anxiety about the meaning and significance of potential illness, not from actual physical presentations 1.
Assessment Approach
When evaluating for IAD, systematically assess:
- History of multiple medical evaluations with consistently normal or benign findings that fail to provide lasting reassurance 1, 2
- Pattern of reassurance-seeking behavior including frequent physician visits, excessive internet searching about symptoms ("cyberchondria"), or repeatedly asking family members for reassurance 2, 4
- Comorbid anxiety or depression, which occurs in 85-90% of cases—screen using GAD-7 and PHQ-9 5, 6, 7
- Family history of anxiety or mood disorders, which represents a significant risk factor 5, 8
- Functional impairment using tools like the Sheehan Disability Scale to quantify impact on work, relationships, and daily activities 5
- Rule out actual medical illness through appropriate (but not excessive) medical workup 1, 2
Common Pitfalls to Avoid
Do not order excessive or unnecessary diagnostic tests in response to patient demands, as this reinforces the illness anxiety cycle and increases healthcare costs without providing therapeutic benefit 1, 2. Instead, build a therapeutic alliance by acknowledging the patient's distress while setting appropriate boundaries around testing 1, 2.
Do not dismiss the patient's concerns as "all in their head"—the anxiety and distress are real and debilitating, even though the feared illness is not present 2, 3. Maintain an empathic, curious, and nonjudgmental stance toward their anxiety 2.
Do not assume brief reassurance will resolve the problem—IAD is chronic and requires structured treatment, not just repeated reassurance that perpetuates the cycle 1, 2, 3.
Treatment Options
Once diagnosed, cognitive behavioral therapy (CBT) is the first-line treatment with the strongest evidence base, demonstrating large effect sizes (Hedges g = 1.01) for health anxiety 5, 8, 6. CBT specifically targets the misinterpretation of bodily sensations and the reassurance-seeking behaviors that maintain the disorder 2, 3.
Pharmacotherapy with SSRIs (such as sertraline or escitalopram) or SNRIs (such as venlafaxine) is an effective alternative or adjunct, particularly when comorbid depression or generalized anxiety is present 5, 8, 2. Start with standard dosing and reassess systematically at 4 and 8 weeks using validated instruments 5, 6.
For moderate symptoms, guided self-help or computerized CBT programs offer accessible alternatives with demonstrated efficacy 8.
Collaboration and Long-term Management
Establish collaboration between medical providers to avoid the pitfall of multiple physicians ordering redundant tests or providing conflicting reassurance 2. Designate a primary provider to coordinate care and set clear boundaries around frequency of visits and testing 1, 2.
IAD is chronic and requires long-term management—educate patients about the nature of the disorder, the expected timeline for treatment response (4-8 weeks for medication, similar for CBT), and the importance of adherence despite delayed onset of improvement 5, 8, 3.