To understand health, we cannot focus on biology alone. The World Health Organization has defined health as a "state of complete physical, mental, and social well-being, and not merely the absence of disease and infirmity." Health and diseases are rooted in the shared meanings of particular cultures. The culture-bound syndrome refers to a diseases or illness that cannot be understood apart from some specific social context.

To fully understand the scope of health and illness in society, we have to consider how society defines illness, what the consequences of such definitions are, and how social position and access to resources shape health outcomes. The sick role refers to societal expectations about the attitudes and behavior of a person viewed as being ill. Physicians and nurses have the power to label people as healthy or sick, and thus to function as gatekeepers for the sick role. Factors such as gender, age, social class, and ethnic group all influence patients' judgments regarding their own state of health. Theorists use the phrase "medicalization of society" to refer to the growing role of medicine as a major institution of social control. Glaring inequalities in health care around the world are manifested by the brain drain and by the infant mortality rate. Sometimes the power to label and the power to oppress go hand in hand. According to labeling theorists, we can view a variety of life experiences as illnesses or not. Physicians use cues to reinforce their prestige and power. Patients are not passive. The Internet is transforming patient–physician encounters.

Social epidemiology is the study of disease distribution, impairment, and general health status across a population. Social class is clearly associated with differences in morbidity and mortality rates. Studies in the United States and other countries have consistently shown that people in the lower classes have higher rates of mortality and disability. The poor economic and environmental conditions of groups such as African Americans, Hispanics, and Native Americans are manifested in high morbidity and mortality rates. Research indicates that in comparison to men, women experience a higher prevalence of many illnesses. Older people in the United States use health services more often than younger people, and their disproportionate use of the health care system is a critical factor in discussions about reforms in the health care system.

The costs of health care in the United States have skyrocketed in the past 35 years. The popular health movement of the 1830s and 1840s emphasized preventive care and self-help. The American Medical Association (AMA), founded in 1848, institutionalized their authority through standardized programs of education and licensing, thus marginalizing lay practitioners, sectarian doctors, and female physicians in general. Medicare and Medicaid greatly expanded federal involvement in health care financing for needy men, women, and children. The power of medicine and the prestige of doctors have risen together. Just as physicians (mostly male) have maintained dominance in their interaction with patients, they have controlled interaction with nurses (mostly female). While increasing numbers of women are becoming physicians, nursing remains overwhelmingly female. A significant proportion of adults in the United States attempt to maintain good health or respond to illness through the use of alternative health care techniques, including holistic medicine.

The environment people live in has a noticeable impact on their health. Likewise, people have a noticeable effect on their environment. Human ecology is an area of study that is concerned with interrelationships between people and their environment. Sociologists and environmentalists have identified several relationships between the environment and people. Analyzing environmental issues from a world systems approach allows us to better understand the global consequences of differential access to resources. Less affluent nations are forced to exploit their natural resources. Western industrialized nations account for only 12 percent of the world's population, but are responsible for 60 percent of worldwide consumption. The rise in global consumption is tied to a capitalist system that depends upon growth for its survival.

Environmental justice is a legal strategy based on claims that racial minorities are subjected disproportionately to environmental hazards. The poor and oppressed continue to bear the brunt of environmental pollution. Worldwide, more than 1 billion people are exposed to potentially health-damaging levels of air pollution. Over 1.1 billion people lack safe and adequate drinking water. The scientific evidence for global warming is clear, consistent, and compelling, yet we continue to struggle with how seriously we should take it. We can again draw on world systems analysis when it comes to seeing who pays the highest price for global warming. Globalization can be both good and bad for the environment.