Mental illness is described as 'the spectrum of cognitive, emotional, and behavioral conditions that interfere with social and emotional well-being and the lives and productivity of people. Having a mental illness can seriously impair, temporarily or permanently, the mental functioning of a person. Other terms include: 'mental health problem', 'illness', 'disorder', 'dysfunction'.[38]
Health science is the branch of science focused on health. There are two main approaches to health science: the study and research of the body and health-related issues to understand how humans (and animals) function, and the application of that knowledge to improve health and to prevent and cure diseases and other physical and mental impairments. The science builds on many sub-fields, including biology, biochemistry, physics, epidemiology, pharmacology, medical sociology. Applied health sciences endeavor to better understand and improve human health through applications in areas such as health education, biomedical engineering, biotechnology and public health.
As per the Constitution of Canada, health care is mainly a provincial government responsibility in Canada (the main exceptions being federal government responsibility for services provided to aboriginal peoples covered by treaties, the Royal Canadian Mounted Police, the armed forces, and Members of Parliament). Consequently, each province administers its own health insurance program. The federal government influences health insurance by virtue of its fiscal powers – it transfers cash and tax points to the provinces to help cover the costs of the universal health insurance programs. Under the Canada Health Act, the federal government mandates and enforces the requirement that all people have free access to what are termed "medically necessary services," defined primarily as care delivered by physicians or in hospitals, and the nursing component of long-term residential care. If provinces allow doctors or institutions to charge patients for medically necessary services, the federal government reduces its payments to the provinces by the amount of the prohibited charges. Collectively, the public provincial health insurance systems in Canada are frequently referred to as Medicare.[15] This public insurance is tax-funded out of general government revenues, although British Columbia and Ontario levy a mandatory premium with flat rates for individuals and families to generate additional revenues - in essence, a surtax. Private health insurance is allowed, but in six provincial governments only for services that the public health plans do not cover (for example, semi-private or private rooms in hospitals and prescription drug plans). Four provinces allow insurance for services also mandated by the Canada Health Act, but in practice there is no market for it. All Canadians are free to use private insurance for elective medical services such as laser vision correction surgery, cosmetic surgery, and other non-basic medical procedures. Some 65% of Canadians have some form of supplementary private health insurance; many of them receive it through their employers.[16] Private-sector services not paid for by the government account for nearly 30 percent of total health care spending.[17]
Focusing more on lifestyle issues and their relationships with functional health, data from the Alameda County Study suggested that people can improve their health via exercise, enough sleep, maintaining a healthy body weight, limiting alcohol use, and avoiding smoking.[28] Health and illness can co-exist, as even people with multiple chronic diseases or terminal illnesses can consider themselves healthy.[29]

The Affordable Care Act has delivered health insurance for millions who were unable to find affordable coverage on the individual market in the past. And, while we strongly encourage our readers to take advantage of the comprehensive ACA-compliant coverage, we do recognize that there is a segment of the individual market population that is facing daunting rate increases. We realize that their coverage options may be limited.
Sleep is an essential component to maintaining health. In children, sleep is also vital for growth and development. Ongoing sleep deprivation has been linked to an increased risk for some chronic health problems. In addition, sleep deprivation has been shown to correlate with both increased susceptibility to illness and slower recovery times from illness.[46] In one study, people with chronic insufficient sleep, set as six hours of sleep a night or less, were found to be four times more likely to catch a cold compared to those who reported sleeping for seven hours or more a night.[47] Due to the role of sleep in regulating metabolism, insufficient sleep may also play a role in weight gain or, conversely, in impeding weight loss.[48] Additionally, in 2007, the International Agency for Research on Cancer, which is the cancer research agency for the World Health Organization, declared that "shiftwork that involves circadian disruption is probably carcinogenic to humans," speaking to the dangers of long-term nighttime work due to its intrusion on sleep.[49] In 2015, the National Sleep Foundation released updated recommendations for sleep duration requirements based on age and concluded that "Individuals who habitually sleep outside the normal range may be exhibiting signs or symptoms of serious health problems or, if done volitionally, may be compromising their health and well-being."[50]
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.
The Commonwealth Fund, in its annual survey, "Mirror, Mirror on the Wall", compares the performance of the health care systems in Australia, New Zealand, the United Kingdom, Germany, Canada and the U.S. Its 2007 study found that, although the U.S. system is the most expensive, it consistently under-performs compared to the other countries.[6] One difference between the U.S. and the other countries in the study is that the U.S. is the only country without universal health insurance coverage.
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 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]

Jump up ^ Leichter, Howard M. (1979). A comparative approach to policy analysis: health care policy in four nations. Cambridge: Cambridge University Press. p. 121. ISBN 0-521-22648-1. The Sickness Insurance Law (1883). Eligibility. The Sickness Insurance Law came into effect in December 1884. It provided for compulsory participation by all industrial wage earners (i.e., manual laborers) in factories, ironworks, mines, shipbuilding yards, and similar workplaces.
The first government responsibility is the fixing of the rate at which medical expenses should be negotiated, and it does so in two ways: The Ministry of Health directly negotiates prices of medicine with the manufacturers, based on the average price of sale observed in neighboring countries. A board of doctors and experts decides if the medicine provides a valuable enough medical benefit to be reimbursed (note that most medicine is reimbursed, including homeopathy). In parallel, the government fixes the reimbursement rate for medical services: this means that a doctor is free to charge the fee that he wishes for a consultation or an examination, but the social security system will only reimburse it at a pre-set rate. These tariffs are set annually through negotiation with doctors' representative organisations.

Since the late 1970s, the federal Healthy People Initiative has been a visible component of the United States’ approach to improving population health.[11][12] In each decade, a new version of Healthy People is issued,[13] featuring updated goals and identifying topic areas and quantifiable objectives for health improvement during the succeeding ten years, with assessment at that point of progress or lack thereof. Progress has been limited to many objectives, leading to concerns about the effectiveness of Healthy People in shaping outcomes in the context of a decentralized and uncoordinated US health system. Healthy People 2020 gives more prominence to health promotion and preventive approaches and adds a substantive focus on the importance of addressing social determinants of health. A new expanded digital interface facilitates use and dissemination rather than bulky printed books as produced in the past. The impact of these changes to Healthy People will be determined in the coming years.[14]