Tehran University of Medical Sciences Traditional and Integrative Medicine 2476-5104 11 2 2026 06 30 2240 2240 S Ahmer Department of Ilmul-Amraz, Faculty of Unani Medicine, Aligarh Muslim University, Aligarh, India Hina Kafeel Department of Ilmul-Amraz, Faculty of Unani Medicine, Aligarh Muslim University, Aligarh, India 2025 07 10 2026 02 26 Hypothyroidism is not clearly defined in Unani and Persian medical literature, and there is a significant lack of standardized tools to assess Sū’-i-Mizāj (abnormal temperament). The objective of this study was to develop and validate a reliable questionnaire grounded in Unani and Persian texts, aimed at identifying Sū’-i-Mizāj in patients with hypothyroidism. This cross-sectional validation study was conducted at Ajmal Khan Tibbiya College and Hospital, Aligarh (2024–2025). Item generation was performed through an extensive review of classical Unani and Persian texts and expert consultation. Content validity was evaluated using the Content Validity Index (CVI). Reliability was assessed through internal consistency (Cronbach's alpha) and test–retest reliability using the Intraclass Correlation Coefficient (ICC) over a two-week interval. Fifty (50) clinically and biochemically diagnosed hypothyroid patients were recruited, of whom 29 completed both test and retest assessments. Ethical approval was obtained from the Institutional Ethics Committee (Approval No. 1401/FUM), and the study was registered with the Clinical Trial Registry of India (CTRI/2024/02/062913). From an initial pool of 61 items, 48 items were retained across six domains after content validation. The overall Scale Content Validity Index (S-CVI/Ave) was 0.89, indicating strong expert agreement. The questionnaire demonstrated high internal consistency (Cronbach's alpha = 0.89) and excellent test–retest reliability (ICC = 0.97; 95% CI: 0.93–0.98). The 48-item Sū’-i-Mizāj questionnaire demonstrates satisfactory content validity and strong reliability in patients with hypothyroidism. However, given the limited sample size and absence of construct and criterion validity analyses, the findings should be considered preliminary. Further large-scale studies are required to confirm the dimensional structure and establish broader clinical applicability. https://jtim.tums.ac.ir/index.php/jtim/article/view/2240