Gerontological nursing is the specialty of nursing pertaining to older adults. Gerontological nurses work in collaboration with older adults, their families, and communities to support healthy aging, maximum functioning, and quality of life. The term gerontological nursing, which replaced the term geriatric nursing is seen as being more consistent with the specialty's broader focus on health and wellness, in addition to illness Gerontological Nursing provides an opportunity to explore the challenges of aging through the lens of transitions. They examine how aging adults respond to transitions such as health challenges, changes in living environments, existential issues, family issues, and dying and death. While physical health issues are addressed, the major emphasis lies in how older adults understand and process transitions in older years and how nurses can facilitate the process for their patients or clients and family members. We also examine the challenges faced by emerging sub-populations of aging adults, such as those with developmental disabilities, the incarcerated, the homeless, as well as those with HIV/AIDS.