Health Anxiety as Reassurance-Seeking Wrong Attractor: Medical Certainty as Unattainable S⁰, Somatic Hypervigilance as Basin Deepener, and the Paradox of Safety Behaviors

We apply the Displacement Framework to health anxiety (illness anxiety disorder), identifying its defining structural feature: the person pursues a ground state — certainty of good health — that is not available in principle. The health ground state S°_health is formalized not as certainty of perfect health but as comfortable uncertainty: the capacity to hold normal bodily variation without catastrophizing.

Health anxiety pursues an impossible S°, guaranteeing permanent displacement. Nine formal propositions are derived covering: S°_health as comfortable uncertainty rather than health certainty, certainty of health as structurally unattainable making health anxiety's S° permanently inaccessible, somatic hypervigilance as basin deepener through interoceptive amplification (formalized as S(t) = S₀(t) + αA(t)), reassurance seeking as wrong-attractor maintenance through tolerance erosion (each reassurance act reduces uncertainty tolerance rather than building it), internet symptom searching as negative D(ξ) spiral, anxiety-induced physiological symptoms (heart rate, muscle tension, GI changes) as self-confirming wrong attractor, the medical investigation cycle as wrong-attractor amplifier (designed to investigate symptoms, it validates the seeking strategy), CBT response prevention as dismantling the reassurance cycle, and ACT uncertainty acceptance as S°_health reconstruction through values-based engagement despite uncertainty.

The counterintuitive therapeutic core — sitting with uncertainty without acting on it — is formalized as traversal of D(ξ_uncertainty) without the wrong-attractor maintenance behavior of checking.