Much in the same manner ought that oligarchy to be established which is next in order: but as to that which is most opposite to a pure democracy, and approaches nearest to a dynasty and a tyranny, as it is of all others the worst, so it requires the greatest care and caution to preserve it: for as bodies of sound and healthy constitutions and ships which are well manned and well found for sailing can bear many injuries without perishing, while a diseased body or a leaky ship with an indifferent crew cannot support the [1321a] least shock; so the worst-established governments want most looking after.
When a clearer distinction is intended, healthy is used to describe the state of the object, and healthful describes its ability to impart health to the recipient. Vegetables in good condition are both healthy (i.e., not rotten or diseased) and healthful (i.e., they improve the eaters' health, compared to eating junk food). By contrast, a poisonous plant can be healthy, but it is not healthful to eat it.
The great positive impact of public health programs is widely acknowledged. Due in part to the policies and actions developed through public health, the 20th century registered a decrease in the mortality rates for infants and children and a continual increase in life expectancy in most parts of the world. For example, it is estimated that life expectancy has increased for Americans by thirty years since 1900,[54] and worldwide by six years since 1990.[55]

No individual applying for health coverage through the individual marketplace will be discouraged from applying for benefits, turned down for coverage or charged more premium because of health status, medical condition, mental illness claims experience, medical history, genetic information or health disability. In addition, no individual will be denied coverage based on race, color, religion, national origin, sex, sexual orientation, marital status, personal appearance, political affiliation or source of income.
The compulsory insurance can be supplemented by private "complementary" insurance policies that allow for coverage of some of the treatment categories not covered by the basic insurance or to improve the standard of room and service in case of hospitalisation. This can include complementary medicine, routine dental treatment and private ward hospitalisation, which are not covered by the compulsory insurance.
Long-term care (Pflegeversicherung[36]) is covered half and half by employer and employee and covers cases in which a person is not able to manage his or her daily routine (provision of food, cleaning of apartment, personal hygiene, etc.). It is about 2% of a yearly salaried income or pension, with employers matching the contribution of the employee.

Systematic activities to prevent or cure health problems and promote good health in humans are undertaken by health care providers. Applications with regard to animal health are covered by the veterinary sciences. The term "healthy" is also widely used in the context of many types of non-living organizations and their impacts for the benefit of humans, such as in the sense of healthy communities, healthy cities or healthy environments. In addition to health care interventions and a person's surroundings, a number of other factors are known to influence the health status of individuals, including their background, lifestyle, and economic, social conditions and spirituality; these are referred to as "determinants of health." Studies have shown that high levels of stress can affect human health.[15]
Private health care has continued parallel to the NHS, paid for largely by private insurance, but it is used by less than 8% of the population, and generally as a top-up to NHS services. There are many treatments that the private sector does not provide. For example, health insurance on pregnancy is generally not covered or covered with restricting clauses. Typical exclusions for Bupa schemes (and many other insurers) include:
The meaning of health has evolved over time. In keeping with the biomedical perspective, early definitions of health focused on the theme of the body's ability to function; health was seen as a state of normal function that could be disrupted from time to time by disease. An example of such a definition of health is: "a state characterized by anatomic, physiologic, and psychological integrity; ability to perform personally valued family, work, and community roles; ability to deal with physical, biological, psychological, and social stress".[7] Then in 1948, in a radical departure from previous definitions, the World Health Organization (WHO) proposed a definition that aimed higher: linking health to well-being, in terms of "physical, mental, and social well-being, and not merely the absence of disease and infirmity".[8] Although this definition was welcomed by some as being innovative, it was also criticized as being vague, excessively broad and was not construed as measurable. For a long time, it was set aside as an impractical ideal and most discussions of health returned to the practicality of the biomedical model.[9]