ICD-116B23	HYPOCHONDRIASIS Hypochondriasis
ICD-10F45.2	Hypochondriacal disorder
DSM-5-TRF45.21	Illness Anxiety Disorder

1. Definition and nosology

Hypochondriasis (ICD-11: 6B23 Hypochondriasis; DSM-5-TR: F45.21 Illness Anxiety Disorder — new name, separated from somatic symptom disorder) — persistent preoccupation and anxiety about having or developing a serious medical illness. The patient either checks repeatedly — clinic visits, internet searches, advice from friends — or, conversely, avoids medical care altogether.

DSM-5 (2013) — hypochondriasis diagnosis split into two new categories:

• Somatic Symptom Disorder (F45.1) — somatic complaints present;
• Illness Anxiety Disorder (F45.21) — somatic symptoms minimal or absent, anxiety dominant.

ICD-11 (2019) — hypochondriasis OCD spectrum included within it (separated from somatoform disorders) — this conceptual transition reflects the evidence base (shared neurobiology and treatment response similar to OCP).

2. History

• Greek medicine — “hypochondrium” (below the ribs) — ancient humoral theory.
• DSM-III (1980) — In the category of somatoform disorders.
• DSM-5 (2013) — separation of illness anxiety disorder and somatic symptom disorder.
• ICD-11 (2019) — transition to the spectrum category of OCD.

3. Epidemiology

• Lifetime prevalence: 1–6% (Bleichhardt G., Hiller W. Compr Psychiatry 2007).
• In primary care patients: ~3–10%.
• Gender: approximately equal.
• Onset: early to middle adulthood.
• Comorbidity: MDD, GAD, OCD, panic disorder.

4. Aetiology and pathogenesis

• Genetic overlap with OCD and anxiety disorders.
• Experience with childhood trauma or medical illnesses.
• Cognitive — catastrophizing of bodily sensations; selective attention; “medical information seeking” (cyberchondria).
• Modeling — high familial vulnerability to illness.

5. Clinical features

• Fear of developing a serious illness (cancer, heart attack, various chronic diseases).
• Interpretation of normal bodily sensations (palpitations, headache, sluggish bowel) as markers of serious illness.
• Behavioral models (two polar):
  • Care-seeking — repeated medical check-ups, multiple doctor consultations (‘doctor shopping’), internet searches (cyberchondria), body checks.
  • Care-avoiding — avoidance of medical check-ups (fear of hearing proof), avoidance of hospitals, medical equipment.
• Medical reassurance provides temporary relief, then anxiety returns.
• Functional impairment — absenteeism from work, social isolation.

6. Diagnosis

6.1 Unified diagnostic criteria

A. Preoccupation with having or developing a serious illness.

B. Somatic symptoms minimal or absent; if present, preoccupation disproportionate to severity.

C. High anxiety about health.

D. The patient exhibits excessive health-related behaviors (checking) or illness avoidance.

E. Duration ≥ 6 months (DSM-5-TR); typical content of the illness may change over time.

F. Not better explained by another mental disorder (MDD, panic, GAD, OCD, BDD, somatic delusions).

6.2 Source-specific clarifications

• DSM-5-TR — Illness Anxiety Disorder (F45.21); care-seeking and care-avoiding subtypes.
• ICD-11 — within the OCD spectrum category (6B23); new placement distinct from classic somatoform location.

6.3 Diagnostic algorithm

1. Clinical interview.
2. Medical evaluation — exclusion of genuine illness (however excessive testing should be avoided).
3. Scale - Whiteley Index, SHAI (Short Health Anxiety Inventory).
4. Comorbidity screening.

6.4 Differential diagnosis

7. Examination and assessment

• Whiteley Index (14 items), SHAI.
• Medical examination — once complete, not repeated.
• PHQ-9, GAD-7 comorbidity.

8. Treatment

1. CBT first-line — cognitive restructuring (catastrophizing), prevention of body checking and reassurance seeking (exposure + ritual prevention), attention training. Effect: Cooper K. et al. Behav Res Ther 2017 meta-analysis.
2. SSRIs — for moderate-to-severe cases or comorbid depression/GAD.
3. Single physician model (single physician) — patient works only with one primary care physician; avoids multiple checks and “doctor shopping”.
4. Reassurance limit — clinician does not provide excessive proof in response to anxiety; short, consistent message.
5. Mindfulness-based approach adjunct.

Source-specific specifications

• Cooper K. et al. Behav Res Ther 2017 meta-analysis — CBT significant effect; medium effect size.
• Greeven A. et al. Am J Psychiatry 2007 RCT — CBT and paroxetine both superior to placebo.

Treatment methods

1. CBT for hypochondriasis — Salkovskis P., Warwick H — Cognitive model — “catastrophization” of bodily sensations central. Intervention: psychoeducation, exploration of alternative explanations, behavioral experiments of body checking and reassurance seeking, exposure. 12–16 sessions.
2. Whiteley Index (Whiteley Index) — 14-item Illness Concern Scale — gold standard screening.
3. Short Health Anxiety Inventory (SHAI) – Salkovskis — 18 items; clinical and population research.
4. Single Physician Model (single physician approach) — The patient works only with one physician; all complaints are managed via that physician; multiple checks and contradictory opinions are prevented.

9. Prognosis

• CBT or SSRIs result in significant improvement in most patients.
• Chronic without treatment; persistent use of medical resources.

10. Myths and misconceptions

Myth 1: “The patient is ‘faking’ illness, playing games”

Evidence: hypochondriasis is a clinical psychiatric disorder; patient’s concern is genuine; not ‘play’ or simulation. Differs from factitious disorder (6D50).

Myth 2: “The more medical tests performed, the more the patient will be reassured”

Evidence: repeated checking gives short-term relief, then anxiety returns; ‘checking dependency’ develops. Single clinician model and check restriction recommended.

Myth 3: “Reassurance (‘you are healthy’) is a treatment tool”

Evidence: repeated reassurance reinforces disorder — patient continues seeking proof. Structured clinician response: one-time assessment, then brief standard message.

Myth 4: “Internet search helps the patient's self-education”

Evidence: “Cyberchondria” — internet searches increase anxiety, enhance catastrophizing; limitation or structuring recommended.

Myth 5: “Hypochondriasis only occurs in elderly patients”

Evidence: onset early-middle adulthood; age range wide.

Myth 6: “Only antidepressants are effective; therapy is useless”

Evidence: Greeven 2007 — CBT and paroxetine both superior to placebo; CBT first-line (long-term effect comparable to SSRIs).

11. Sources

1. WHO. ICD-11. 6B23 Hypochondriasis. 2024.
2. APA. DSM-5-TR. 2022.
3. Cooper K. et al. Cognitive behaviour therapy for health anxiety: a systematic review and meta-analysis. Behav Res Ther 2017;90:8–20.
4. Greeven A. et al. Cognitive behavior therapy and paroxetine in the treatment of hypochondriasis: a randomized controlled trial. Am J Psychiatry 2007;164(1):91–99.
5. Salkovskis P.M., Rimes K.A., Warwick H.M. The Health Anxiety Inventory: development and validation of scales for the measurement of health anxiety and hypochondriasis. Psychol Med 2002;32(5):843–853.