Public health has been described as "the science and art of preventing disease, prolonging life and promoting health through the organized efforts and informed choices of society, organizations, public and private, communities and individuals."[51] It is concerned with threats to the overall health of a community based on population health analysis. The population in question can be as small as a handful of people or as large as all the inhabitants of several continents (for instance, in the case of a pandemic). Public health has many sub-fields, but typically includes the interdisciplinary categories of epidemiology, biostatistics and health services. Environmental health, community health, behavioral health, and occupational health are also important areas of public health.
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]
A contract between an insurance provider (e.g. an insurance company or a government) and an individual or his/her sponsor (e.g. an employer or a community organization). The contract can be renewable (e.g. annually, monthly) or lifelong in the case of private insurance, or be mandatory for all citizens in the case of national plans. The type and amount of health care costs that will be covered by the health insurance provider are specified in writing, in a member contract or "Evidence of Coverage" booklet for private insurance, or in a national health policy for public insurance.
The environment is often cited as an important factor influencing the health status of individuals. This includes characteristics of the natural environment, the built environment and the social environment. Factors such as clean water and air, adequate housing, and safe communities and roads all have been found to contribute to good health, especially to the health of infants and children.[19][30] Some studies have shown that a lack of neighborhood recreational spaces including natural environment leads to lower levels of personal satisfaction and higher levels of obesity, linked to lower overall health and well being.[31] This suggests that the positive health benefits of natural space in urban neighborhoods should be taken into account in public policy and land use.
Jump up ^ World Health Organization.Constitution of the World Health Organization as adopted by the International Health Conference, New York, 19–22 June 1946; signed on 22 July 1946 by the representatives of 61 States (Official Records of the World Health Organization, no. 2, p. 100) and entered into force on 7 April 1948. In Grad, Frank P. (2002). "The Preamble of the Constitution of the World Health Organization". Bulletin of the World Health Organization. 80 (12): 982.
The resulting programme is profession-based: all people working are required to pay a portion of their income to a not-for-profit health insurance fund, which mutualises the risk of illness, and which reimburses medical expenses at varying rates. Children and spouses of insured people are eligible for benefits, as well. Each fund is free to manage its own budget, and used to reimburse medical expenses at the rate it saw fit, however following a number of reforms in recent years, the majority of funds provide the same level of reimbursement and benefits.
In the late 1990s and early 2000s, health advocacy companies began to appear to help patients deal with the complexities of the healthcare system. The complexity of the healthcare system has resulted in a variety of problems for the American public. A study found that 62 percent of persons declaring bankruptcy in 2007 had unpaid medical expenses of $1000 or more, and in 92% of these cases the medical debts exceeded $5000. Nearly 80 percent who filed for bankruptcy had health insurance.[57] The Medicare and Medicaid programs were estimated to soon account for 50 percent of all national health spending.[58] These factors and many others fueled interest in an overhaul of the health care system in the United States. In 2010 President Obama signed into law the Patient Protection and Affordable Care Act. This Act includes an 'individual mandate' that every American must have medical insurance (or pay a fine). Health policy experts such as David Cutler and Jonathan Gruber, as well as the American medical insurance lobby group America's Health Insurance Plans, argued this provision was required in order to provide "guaranteed issue" and a "community rating," which address unpopular features of America's health insurance system such as premium weightings, exclusions for pre-existing conditions, and the pre-screening of insurance applicants. During 26–28 March, the Supreme Court heard arguments regarding the validity of the Act. The Patient Protection and Affordable Care Act was determined to be constitutional on 28 June 2012. SCOTUS determined that Congress had the authority to apply the individual mandate within its taxing powers.[59]
Comprehensive health insurance pays a percentage of the cost of hospital and physician charges after a deductible (usually applies to hospital charges) or a co-pay (usually applies to physician charges, but may apply to some hospital services) is met by the insured. These plans are generally expensive because of the high potential benefit payout — $1,000,000 to $5,000,000 is common — and because of the vast array of covered benefits.

Many teens suffer from mental health issues in response to the pressures of society and social problems they encounter. Some of the key mental health issues seen in teens are: depression, eating disorders, and drug abuse. There are many ways to prevent these health issues from occurring such as communicating well with a teen suffering from mental health issues. Mental health can be treated and be attentive to teens' behavior.[40]

The Commonwealth Fund completed its thirteenth annual health policy survey in 2010.[8] A study of the survey "found significant differences in access, cost burdens, and problems with health insurance that are associated with insurance design".[8] Of the countries surveyed, the results indicated that people in the United States had more out-of-pocket expenses, more disputes with insurance companies than other countries, and more insurance payments denied; paperwork was also higher although Germany had similarly high levels of paperwork.[8]
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.

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]
Genetics, or inherited traits from parents, also play a role in determining the health status of individuals and populations. This can encompass both the predisposition to certain diseases and health conditions, as well as the habits and behaviors individuals develop through the lifestyle of their families. For example, genetics may play a role in the manner in which people cope with stress, either mental, emotional or physical. For example, obesity is a significant problem in the United States that contributes to bad mental health and causes stress in the lives of great numbers of people[32]. (One difficulty is the issue raised by the debate over the relative strengths of genetics and other factors; interactions between genetics and environment may be of particular importance.)
With regular health insurance plans, you could face considerable out-of-pocket expenses which is why having a critical illness insurance plan can be beneficial. Unlike traditional health insurance, which reimburses the insured or provider for covered claims, critical illness insurance pays you directly if you're diagnosed with a covered critical illness and there are no copays or deductibles. Your insurer typically makes a lump sum cash payment for serious medical issues such as a heart attack, stroke, and cancer.
Health, as defined by the World Health Organization (WHO), is "a state of complete physical, mental and social well-being and not merely the absence of disease or infirmity."[1][2] This definition has been subject to controversy, as it may have limited value for implementation.[3][4][5] Health may be defined as the ability to adapt and manage physical, mental and social challenges throughout life.[6]