Gerontology is the study of the social, psychological and biological aspects of aging. It is distinguished from geriatrics, which is the branch of medicine that studies the disease of the elderly.

Gerontology encompasses the following:

• studying physical, mental, and social changes in people as they age;
• investigating the aging process itself (biogerontology);
• investigating the interface of normal ageing and age-related disease (geroscience);
• investigating the effects of our aging population on society, including the fiscal effects of pensions, entitlements, life and health insurance, and retirement planning;
• applying this knowledge to policies and programs, including a macroscopic (i.e. government planning) and microscopic (i.e. running a nursing home) perspective.

The multidisciplinary focus of gerontology means that there are a number of sub-fields, as well as associated fields such as psychology and sociology that also cross over into gerontology. However, that there is an overlap should not imply that they are the same. The field of gerontology was developed relatively late, and as such often lacks the structural and institutional support needed. However, the huge increase in the elderly population in the post-industrial Western nations has led to this becoming one of the most rapidly growing fields.

Biogerontology

Biogerontology is a sub-field of gerontology studying the biological processes of aging. It is composed of the interdisciplinary research on biological aging’s causes, effects, and mechanisms in order to better understand human senescence. Biogerontologists usually work at research universities or laboratories. While the majority of biogerontologists have a PhD, some have an MD. Some within biogerontology have worked to show that aging is a biological process that we are far from being able to control.

Biomedical gerontology, also known as experimental gerontology and life extension, is a sub discipline of biogerontology that endeavors to slow, prevent, and even reverse aging in both humans and animals. Curing age-related diseases is one approach, and slowing down the underlying processes of aging is another. Most “life extensionists” believe the human life span can be altered within the next century, if not sooner. “Optimists” such as Aubrey DeGrey are of the opinion that the first person to reach one thousand years of age has already been born. Some biogerontologists take an intermediate position, emphasizing the study of the aging process as a means of mitigating aging-associated diseases, while either claiming that maximum life span can not be altered or that it is undesirable to try.

Medical gerontology: Geriatrics

Geriatrics is a sub-specialty of medicine that focuses on health care of the elderly. It aims to promote health and to prevent and treat diseases and disabilities in older adults. Geriatrics was separated from internal medicine as a distinct entity in the same way that neonatology is separated from pediatrics.

There is no set age at which patients may be under the care of a geriatrician. Rather, this is determined by a profile of the typical problems that geriatrics focuses on. The term geriatrics differs from gerontology, which is the study of the aging process itself. However “Geriatrics” is considered by some as “Medical Gerontology”.

Geriatrics differs from adult medicine in many respects. The body of an elderly person is substantially different physiologically from that of an adult. Old age is the period of manifestation of decline of the various organ systems in the body. This varies according to various reserves in the organs, as smokers, for example, consume their respiratory system reserve early and rapidly.

Social gerontology

Social gerontology is a multi-disciplinary sub-field that specializes in studying or working with older adults.

Social gerontologists may have degrees or training in social work, nursing, psychology, sociology, demography, gerontology, or other social science disciplines. Social gerontologists are responsible for educating, researching, and advancing the broader causes of older people by giving informative presentations, publishing books and articles that pertain to the aging population, producing relevant films and television programs, and producing new graduates of these various disciplines in college and university settings.

Because issues of life span and life extension need numbers to quantify them, there is an overlap with demography. Those that study the demography of the human life span are different than those that study the social demographics of aging.