Geriatrics is the branch of medicine that focuses on health promotion and the prevention and treatment of disease and disability in later life. The term itself can be distinguished from gerontology, which is the study of the aging process itself. The term comes from the Greek "geros" meaning "old man" and "iatros" meaning "healer."

In the USA, geriatricians are primary care physicians who are board-certified in either Family Practice or Internal Medicine and have also acquired the additional training necessary to obtain the Certificate of Added Qualifications (CAQ) in Geriatric Medicine.

In the United Kingdom, most geriatricians are hospital physicians, while some focus on community geriatrics. While originally a distinct clinical specialty, it has been integrated as a specialism of general medicine since the late 1970s (Barton & Mulley 2003). Most geriatricians are therefore accredited for both. Specialized geriatrics services include orthogeriatrics (close cooperation with orthopedic surgery and a focus on osteoporosis and rehabilitation), psychogeriatrics (focus on dementia, depression and other conditions common in the elderly), and rehabilitation.