Health care is the maintenance or improvement of health via the prevention, diagnosis, treatment, amelioration or cure of disease, illness, injury, and other physical and mental impairments in people. Health care is delivered by health professionals and allied health fields. Medicine, dentistry, pharmacy, midwifery, nursing, optometry, audiology, psychology, occupational therapy, physical therapy, athletic training, and other health professions all constitute health care. It includes work done in providing primary care, secondary care, and tertiary care, as well as in public health.

1. Health care is the maintenance or improvement of health via the prevention, diagnosis,
treatment, amelioration or cure of disease, illness, injury, and other physical and mental
impairments in people. Health care is delivered by health professionals and allied health
fields. Medicine, dentistry, pharmacy, midwifery, nursing, optometry, audiology,
psychology, occupational therapy, physical therapy, athletic training, and other health
professions all constitute health care. It includes work done in providing primary care,
secondary care, and tertiary care, as well as in public health.
The healthcare industry incorporates several sectors that are dedicated to providing
health care services and products. As a basic framework for defining the sector, the
United Nations' International Standard Industrial Classification categorizes health care
as generally consisting of hospital activities, medical and dental practice activities, and
"other human health activities." The last class involves activities of, or under the
supervision of, nurses, midwives, physiotherapists, scientific or diagnostic laboratories,
pathology clinics, residential health facilities, patient advocates or other allied health
professions.
Health care is a major economic sector in most countries. In the United States, for
example, health care spending accounted for 17.9% of GDP in 2020. This is
significantly higher than the average of 11.5% for OECD countries. The high cost of
health care in the United States is due to a number of factors, including the aging
population, the rising cost of medical technology, and the increasing prevalence of
chronic diseases.
There are a number of different ways to finance health care. In some countries, health
care is funded by the government through taxes. In other countries, health care is
funded by private insurance companies. There are also a number of hybrid systems,
where both the government and private insurers play a role in financing health care.
The delivery of health care can also vary from country to country. In some countries,
there is a single-payer system, where the government is the sole payer for health care
services. In other countries, there are multiple payers, including the government, private
insurers, and individuals.
The quality of health care can also vary from country to country. In general, developed
countries have higher quality health care than developing countries. However, there are
also significant differences in the quality of health care within developed countries. For
example, the quality of health care in the United States is often considered to be lower
than the quality of health care in other developed countries.
There are a number of challenges facing the global health care system. These
challenges include the aging population, the rising cost of medical technology, the

2. increasing prevalence of chronic diseases, and the lack of access to health care in
developing countries.
Despite these challenges, the global health care system has made significant progress
in recent years. Life expectancy has increased, the number of people dying from
preventable diseases has decreased, and access to health care has improved in many
parts of the world.
The future of health care is uncertain. However, it is likely that the global health care
system will continue to evolve in response to the challenges and opportunities of the
21st century.