Quick Answer: Health care, or healthcare, is the improvement or maintenance 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. The term includes work done in providing primary care, secondary care, tertiary care, mental health care and public health. Access to health care may vary across countries, communities, and individuals, influenced by social and economic conditions and health policies. Providing health care services means "the timely use of personal health services to achieve the best possible health outcomes".