Complex Chronic Disease (CCD) is a condition involving multiple morbidities that requires the attention of multiple health care providers or facilities, and possibly home-based care.
A patient with CCD presents to the health care system with unique needs, disabilities, or functional limitations.
A CCD typically involves multiple self-management requirements or complex social support needs, or both.

See reference for details.

M A Sevick, JM Trauth, BS Ling, RT Anderson, GA Piatt. Patients with Complex Chronic Diseases: Perspectives on Supporting Self-Management. J Gen Intern Med. 2007 December; 22 (Suppl 3): 438–444. Internet. Accessed on October 16, 2012.