Private health care refers to medical services and insurance provided by non-governmental entities. When individuals purchase insurance from a private company, they are participating in the private health care market, which operates independently of state-funded or public health systems.

Talcott Parsons introduced the concept of the 'sick role' in his 1951 work, 'The Social System.' This functionalist perspective describes how society views illness as a form of deviance that requires the individual to be temporarily excused from normal social obligations, provided they seek professional medical help.

In the social model of disability, 'impairment' refers to the physical or mental limitation or loss of function that an individual experiences. It is distinguished from 'disability,' which is the social disadvantage or exclusion caused by societal barriers that fail to accommodate those limitations.

Anorexia nervosa, a serious eating disorder characterized by restrictive eating and low body weight, was first identified as a distinct medical condition in the 19th century. This marked a significant shift in clinical understanding and addressing the condition, paving the way for further research and treatment protocols that continue to evolve in modern medicine.

The 'Sick Role' is a concept introduced by Talcott Parsons. It outlines the rights and obligations of a sick person, such as being exempt from normal social responsibilities while having the duty to seek professional help and cooperate with treatment.

Millennium Development Goal 5 was specifically established by the United Nations to improve maternal health globally. This goal focused on reducing maternal mortality ratios and achieving universal access to reproductive health services by the year 2015, distinguishing it from other goals that targeted child health or specific infectious diseases.

Disability is defined as a physical or mental impairment that substantially limits one or more major life activities. While 'disease' refers to a biological pathology and 'illness' refers to the subjective experience of being unwell, 'disability' specifically highlights the functional limitation or the social barrier that prevents an individual from performing everyday tasks effectively within their environment.

Gerontology is the interdisciplinary study of aging, focusing on the biological, psychological, and social aspects of the aging process. It examines how aging affects individuals and how societal structures, such as healthcare and social security, adapt to the needs of an aging population. This field is increasingly important as life expectancies rise globally.

The United States healthcare system is frequently described as complex due to its fragmented nature, involving a mix of private insurance, government programs like Medicare and Medicaid, and various providers. This complexity arises from the interplay of economic, political, and social factors that influence access, quality, and cost, making it a multifaceted institution that is difficult to navigate for many citizens.

Gerontology is the comprehensive study of the aging process. Because aging affects every aspect of human life, it requires a multidisciplinary approach. Medical and biological scientists study the physical changes, social scientists examine the societal impact and roles of the elderly, and economists analyze the financial implications of aging populations, such as pension systems and healthcare costs.