ObjectiveTo explore the potential association between social restrictions and FCR in patients who underwent HSCT, and preliminarily investigate whether examine whether illness perception and cognitive emotion regulation mediate this association using an exploratory cross-sectional design.MethodsWe retrospectively collected clinical data from 328 patients who underwent HSCT at the Department of Hematology, the First Affiliated Hospital of Chongqing Medical University, between January 2020 and December 2024. After excluding three invalid cases with incomplete core data, 325 patients were included in the analysis. All participants completed the SCS, IPQ-R, CERQ, and FCRI assessments. We constructed a chain mediation model for exploratory analysis. A sensitivity analysis adjusting for age, sex, and transplant type was further conducted to control for confounding.ResultsOf the 325 patients, 172 experienced mild FCR (52.92%), 128 experienced moderate FCR (39.38%), and 25 experienced severe FCR (7.69%). The SCS, IPQ-R, CERQ, and FCRI scores were all positively correlated with each other in patients who underwent HSCT (all P < 0.05). Mediation analysis showed that SCS scores were significantly positively associated with IPQ-R scores, with a small effect size (R = 0.135, R²=0.018, F = 6.033, P = 0.015). The total statistical association value of social restrictions with FCR was 0.816, with a Bootstrap 95% CI (0.640-0.993) excluding 0. The direct association value was 0.780, and the Bootstrap 95% CI (0.593~0.966) excluding 0. The hypothesized SCS→IPQ-R→CERQ→FCR chain mediation pathway was not statistically supported. After adjusting for age, sex, and transplant type, all indirect pathways lost statistical significance, while the direct positive association between social restrictions and FCR remained significant (direct effect=0.252, 95%CI: 0.028–0.475, P = 0.028).ConclusionThe prevalence of moderate-to-severe FCR in patients after HSCT is 47.08%. This exploratory study suggests that social restrictions are statistically associated with FCR. The pre-specified chain mediation model was not confirmed after adjusting for covariates. The causal direction and clinical significance of the findings remain to be verified by longitudinal studies.