Health

Health is the overall condition of a person's or group's body and mind. It is typically defined not merely as the absence of disease, but also as the capacity of an individual to work daily, interact with others, and adapt to life changes.

The most widely recognized international definition is that of the World Health Organization (WHO), which describes health as a state of complete physical, mental, and social well-being, not merely the absence of disease or infirmity. This definition is used as a policy framework, though it is also debated as being too broad and difficult to measure precisely.

Factors affecting health

Health is not determined by genetics and medical care alone. Social and economic factors influence it—including income, education, employment, housing, access to clean water, sanitation, and food. These are known as social determinants of health. Environment also plays a role: air quality, climate, and disease prevalence in a given area.

Mental health

Mental health encompasses emotional well-being, thinking, and social connection. Conditions such as depression and anxiety affect work and education capacity. In many places, mental health services have fewer resources and staff than physical health services, and people often face social stigma when seeking mental health care.

Health systems

A health system consists of hospitals, primary health clinics, staff, medicines, information systems, and funding. Some countries rely on public funding or insurance schemes, while in others patients pay out-of-pocket for services. The term universal health coverage refers to the goal that all people have access to necessary health services without financial hardship.

Measurement and statistics

Population health is measured using indicators such as life expectancy, infant and maternal mortality, vaccination coverage, and disease burden. These data come from birth and death registries, household surveys, and reports from health facilities. Where registration is incomplete, statistical models are used to estimate figures, which can vary between different sources.