Illness Anxiety Disorder

Illness anxiety disorder (IAD) is a DSM-5-TR diagnosis characterized by preoccupation with having or acquiring a serious illness, when physical (somatic) symptoms are absent or only mild. The person is easily alarmed about their health and either repeatedly checks for signs of illness or avoids anything that might bring the fear to mind. It replaced part of the older diagnosis of hypochondriasis, which DSM-5 retired in 2013. What sets IAD apart is that fear and preoccupation, rather than physical complaints, are at the center.

For a broader, everyday overview of health worries and how they range from mild to severe, see health anxiety. This page focuses on the formal diagnosis: how clinicians define it, how it differs from related conditions, why it persists and how it is treated. It is educational and cannot be used to diagnose yourself.

DSM-5-TR Diagnostic Criteria

DSM-5-TR lists illness anxiety disorder in the chapter on somatic symptom and related disorders. All of the following are required:

1. Preoccupation with having or acquiring a serious illness.
2. Somatic symptoms are not present or, if present, are only mild. If another medical condition is present or there is a high risk of developing one, such as a strong family history, the preoccupation is clearly excessive or disproportionate.
3. A high level of anxiety about health, with the person easily alarmed about their health status.
4. Excessive health-related behaviors, such as repeatedly checking the body for signs of illness, or maladaptive avoidance, such as avoiding doctor's appointments and hospitals.
5. The preoccupation has been present for at least six months, although the specific illness feared may change during that time.
6. The preoccupation is not better explained by another mental disorder, such as somatic symptom disorder, panic disorder, generalized anxiety disorder, body dysmorphic disorder, OCD or delusional disorder.

ICD-11

ICD-11 takes a different approach. It keeps the term hypochondriasis (also called health anxiety disorder) and places it among the obsessive-compulsive or related disorders, reflecting the repetitive checking and reassurance-seeking that resemble compulsions. This difference between the two systems reflects an ongoing debate about how best to classify health anxiety.

Subtypes

DSM-5-TR asks clinicians to specify one of two types.

Care-seeking type

• Frequent medical visits, tests and procedures.
• Repeated requests for scans, second opinions and referrals.
• Persistent reassurance-seeking from family, friends or health professionals.
• Body-checking, such as feeling for lumps, examining skin or monitoring pulse.
• Extensive online symptom searching.

Care-avoidant type

• Avoidance of routine medical care, screenings and check-ups for fear of what might be found.
• Avoidance of hospitals, sick relatives or news stories about illness.
• Reluctance to discuss bodily sensations.
• A risk that genuine medical problems are diagnosed late.

IAD vs. Somatic Symptom Disorder

DSM-5 divided former hypochondriasis into two diagnoses depending on whether physical symptoms are prominent:

The DSM-5 work group estimated that most people previously diagnosed with hypochondriasis, often cited as around three-quarters, would meet criteria for somatic symptom disorder, with the rest meeting criteria for IAD.

Cyberchondria

Cyberchondria describes repeated, escalating online searching for health information that increases rather than relieves anxiety. It is not a formal diagnosis but is a common maintaining behavior in IAD. Typical features include:

• Searching symptoms repeatedly on search engines and forums.
• Focusing on the most serious possible explanations.
• Brief relief followed by renewed searching.
• Searching that takes up significant time and disrupts sleep or work.

Search results tend to highlight rare, frightening conditions, which feeds catastrophic thinking and the availability heuristic, the tendency to judge something more likely because examples come easily to mind.

Differential Diagnosis

• Somatic symptom disorder: distinguished by prominent physical complaints.
• Generalized anxiety disorder: worry spans many areas, not only health.
• OCD: intrusive thoughts about illness or contamination take an obsessive-compulsive form, often with other obsessions.
• Body dysmorphic disorder: preoccupation focuses on appearance, not illness.
• Major depressive disorder: health worries occur only during a depressive episode.
• Panic disorder: fears center on an immediate catastrophe during attacks rather than long-term disease.
• Delusional disorder, somatic type: beliefs are held with delusional certainty and are not open to any doubt.
• Medical conditions: appropriate investigation is always needed for new or changing symptoms.

Etiology and Maintenance

Predisposing factors

• Early experiences of serious illness, either personally or in a parent or caregiver.
• Medical trauma or past experiences of missed or late diagnoses.
• Family patterns, such as parents who were highly anxious about health.
• Temperament, including high trait anxiety, neuroticism and difficulty tolerating uncertainty.
• Recent stress or loss, such as the death or illness of someone close.

Cognitive maintenance model

Paul Salkovskis and Hilary Warwick (1986) developed an influential cognitive model of health anxiety. It describes a cycle:

1. Normal bodily sensations or minor changes are noticed, often because attention is focused on the body.
2. The sensations are interpreted as signs of serious disease.
3. Anxiety rises, which produces more bodily sensations and narrows attention further.
4. Safety behaviors, such as checking, reassurance-seeking and searching, bring brief relief.
5. The relief reinforces those behaviors and prevents the person from learning that the feared illness is unlikely or that uncertainty is tolerable.

Assessment

Clinicians typically combine an interview with questionnaires and a review of medical history.

• Short Health Anxiety Inventory (SHAI): an 18-item questionnaire developed from the Health Anxiety Inventory (Salkovskis et al., 2002).
• Whiteley Index: a classic measure of hypochondriacal concerns developed by Issy Pilowsky (1967).
• Illness Attitudes Scales: assess fears, beliefs and behaviors about illness.
• Functional analysis: mapping triggers, checking, reassurance-seeking and avoidance.
• Medical record review and coordination with primary care.

These tools support clinical judgment; scores alone do not make a diagnosis. See mental health screening for how such measures are used.

Evidence-Based Treatment

Cognitive behavioral therapy (first-line)

CBT for health anxiety has the strongest evidence base. In a large UK trial in hospital medical clinics, Tyrer and colleagues (2014) found that CBT for health anxiety, delivered by trained nurses and other staff, produced greater reductions in health anxiety than usual care, with benefits lasting at least two years. Meta-analyses also support internet-delivered CBT. Core components include:

• Psychoeducation about the cognitive model and the role of reassurance.
• Cognitive restructuring of catastrophic interpretations.
• Exposure to feared sensations and illness-related cues, such as reading about a disease or visiting a hospital.
• Response prevention: gradually reducing checking, reassurance-seeking and online searching, similar to exposure and response prevention for OCD.
• Behavioral experiments to test predictions, such as what happens to a sensation when it is not checked.
• Building tolerance of uncertainty, sometimes using mindfulness-based techniques.

Medication

Some medications have shown benefit for health anxiety in clinical trials, and a doctor may discuss medication as an option, alone or with CBT, particularly when anxiety is severe or depression is also present. Decisions about medication should be made with a prescribing clinician.

Primary care management

• Regular scheduled appointments rather than symptom-driven visits.
• Focused visits that emphasize daily functioning.
• Avoiding unnecessary tests that can feed the cycle, while still investigating genuinely new symptoms.
• Consistent messages across all health professionals involved.
• Acknowledging that the distress is real, even when the feared illness is not present.

Course and Prognosis

Without treatment, IAD tends to be chronic, with periods of greater and lesser intensity, often worsening during stressful times or after illness in others. The specific feared disease may change over time. Co-occurring depression and other anxiety disorders are common. With CBT, many people improve substantially and studies show gains are often maintained, though some continue to have residual worries. People with the care-avoidant type face the additional risk of delayed diagnosis of genuine medical conditions.

Conclusion

Illness anxiety disorder refines the older concept of hypochondriasis by focusing on people whose main difficulty is fear and preoccupation rather than physical symptoms. The key insight from cognitive research is that reassurance, whether from doctors, tests, body-checking or online searching, provides short-lived relief that keeps the fear going. Effective treatment helps people reduce those behaviors and build tolerance for uncertainty. Anyone struggling with persistent health worries can start by talking with a primary care doctor or a mental health professional.