Cambridge Health Alliance | 24,260 followers on LinkedIn. CHA is a vibrant, innovative health system serving the greater Boston region. We believe in equity and excellence. | Cambridge Health Alliance (CHA) is a vibrant, innovative health system that serves everyone in our communities. With over 140,000 patients in Boston’s metro-north region served by two hospital campuses and a network of primary and specialty care centers, CHA is proud to provide the health care people need most in their lives.