TY - JOUR T1 - Federated Learning for Healthcare: A Critical Review of Privacy Guarantees, Heterogeneity Challenges, and the Research–Deployment Gap AU - Khaled Mahfouz AU - Rania Abdelaziz AU - Sherif Adel AU - Dina Mostafa AU - Tamer Nabil AU - Reem Saad JF - Journal of Artificial Intelligence for Healthcare Systems JO - J. Artif. Intell. Healthc. Syst. SN - 3149-8981 Y1 - 2025 VL - 4 IS - 1 SP - 97 N2 - Federated learning (FL) is promoted as a privacy-preserving method for training machine learning models across healthcare institutions without sharing patient data, with growing use in medical imaging, electronic health records, and rare disease research. This critical review examines FL studies from 2017–2024, focusing on privacy guarantees, statistical heterogeneity, communication efficiency, and real-world clinical deployment. A structured search of PubMed, IEEE Xplore, arXiv, and Google Scholar was conducted using relevant FL and healthcare terms, including studies addressing privacy, heterogeneity, communication, or deployment. Reported privacy guarantees are often overstated, with most studies relying on FedAvg without differential privacy. Statistical heterogeneity in non-IID settings remains largely unresolved. Fewer than 5% of studies report real-world deployment, typically at very small scale. A significant gap exists between FL research and clinical application. Current methods fall short of healthcare-grade privacy and real-world constraints, limiting readiness for high-stakes clinical use. UR - https://cirpublications.com/i028497975 ER -