This chapter provides an overview of delirium and dementia, including primary dementias, secondary dementias, and reversible dementias. The distinction between mild and major neurocognitive disorders is described. An in-depth description of Alzheimer’s disease, including etiology, treatment, and general guidelines for care, is included. Other dementias including Huntington’s disease, frontotemporal lobar degeneration, Lewy body disease, Creutzfeldt-Jakob disease, and vascular dementia are also briefly covered. Secondary dementias (e.g., dementia associated with Parkinson’s disease) and reversible dementias (e.g., normal pressure hydrocephalus) conclude the chapter.

An overview of the gastrointestinal system as it relates to the nutritional status of the older individual is presented. The anatomy and physiology and age-related changes of the system are reviewed. Selected common age-related disorders are discussed along with their incidence, presenting symptoms, diagnostic measures, and interventions. The American Cancer Society’s 2020 screening recommendations for the intestines are then outlined.

An overview of the anatomy, physiology, and functioning of the respiratory system is provided. Age-related changes in the respiratory system along with selected specific disorders commonly experienced by older adults and measures useful in preventing and living with respiratory dysfunctions are explained.

Significance of changes in biological, psychological, and social aging and their impact on lessened reserve capacity; the importance of understanding slowness, stress, pacing, and accidents in working with older adults; and the role of health promotion, disease prevention, and health maintenance in successful aging conclude the chapter.

An overview of the anatomy, physiology, and function of the urinary system and age-related changes is provided. Selective disorders common in older adults with description and common symptoms are discussed. Useful diagnostic procedures and treatments frequently prescribed to maintain urinary health in older age were elaborated.

Health promotion, exercise, and the need to focus on these to enhance a healthy long life are discussed. Identification of significant areas of health promotion and barriers to achieving good health are presented. Next, disease prevention along with primary, secondary, tertiary, and quaternary preventive measures are listed. Healthy People 2030, the fifth national health initiative, and its objectives are outlined along with the Patient Protection and Affordable Care Act. Exercise, its meaning, and value in modifying age-related changes are briefed. Types of exercise programs; isometric, isotonic, and aerobic and their recommended use by older adults are listed.

The anatomy, physiology, and functions of the endocrine system are reviewed. Age-related changes and specific disorders are grouped together to better understand their impact on the system and health of the older adults. Special attention is given to hyperthyroidism, hypothyroidism, and prediabetes and type 1 and type 2 diabetes. Recommended care for diabetics is also outlined.

Brief anatomy and physiology of each sensory systems is described. The effects of aging on each sense and the implications for older adults are detailed. More commonly experienced aging-related diseases that affect sensory function in older adults, along with their respective treatments, are also discussed including cataracts, glaucoma, advanced macular degeneration, tinnitus, and Ménière’s disease.

The field of gerontechnology is described along with how research endeavors can be aided by gerontechnology. Practical applications that enhance the daily life of older adults and their caregivers are also discussed. Caveats of appropriate use of gerontechnology are considered. The chapter concludes with discussion of family technologists who can support older adults and their primary caregivers.

Anatomy and physiology of the nervous system, including the central nervous system and peripheral nervous system, are described. Age-related changes in the nervous system are described. Common nervous system disorders are briefly discussed with Parkinson’s disease covered in greater depth. Sleep, aging-related changes with sleep, sleep disorders, and dangerous consequences of untreated sleep disorders are highlighted. The chapter concludes with brief consideration of how aging impacts memory and learning.