Self-consciousness regarding health status is crucial for individuals with Type 2 Diabetes Mellitus (T2DM) to engage actively in lifelong diabetes self-management. However, existing instruments have not fully incorporated aspects of nurse partnership, dialogue, and pattern recognition related to diabetes knowledge, self-management skills, and self-care abilities. This study aimed to develop and validate the Self-Consciousness of Health Status (SCHS) instrument for patients with T2DM and chronic complications. Instrument development occurred in three phases: Phase One involved a literature review and a three-round e-Delphi to generate the item pool. Phase Two tested content validity with five experts, and construct validity with confirmatory factor analysis (CFA) among 602 participants. Internal consistency and test-retest reliability were also assessed. Phase Three finalized the scale and score interpretation. CFA confirmed the SCHS structure, consisting of 77 items across four dimensions. The scale demonstrated strong model fit (Chi Square p > 0.05, RMSEA p > 0.05) and standardized factor loadings between 0.516–0.908 (p < 0.05). SCHS is a valid and reliable tool to measure health self-consciousness in patients with T2DM and chronic complications. © the Author(s), 2025.