The integration of swarm intelligence (SI) with the Internet of Medical Things (IoMT) is opening new avenues for intelligent, cooperative healthcare solutions. This comprehensive review surveys the application of SI algorithms—such as particle swarm optimization, ant colony optimization, and artificial bee colony—in IoMT contexts. The paper highlights how swarm-inspired approaches can enhance resource allocation, anomaly detection, patient monitoring, and decision support in distributed healthcare systems. Key challenges, including scalability, security, and energy efficiency, are discussed along with future research directions, positioning SI as a cornerstone for next-generation IoMT-based smart healthcare ecosystems.