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.
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.
A recent study by PricewaterhouseCoopers examining the drivers of rising health care costs in the U.S. pointed to increased utilization created by increased consumer demand, new treatments, and more intensive diagnostic testing, as the most significant. However, Wendell Potter, a long-time PR representative for the health insurance industry, has noted that the group which sponsored this study, AHIP, is a front-group funded by various insurance companies. People in developed countries are living longer. The population of those countries is aging, and a larger group of senior citizens requires more intensive medical care than a young, healthier population. Advances in medicine and medical technology can also increase the cost of medical treatment. Lifestyle-related factors can increase utilization and therefore insurance prices, such as: increases in obesity caused by insufficient exercise and unhealthy food choices; excessive alcohol use, smoking, and use of street drugs. Other factors noted by the PWC study included the movement to broader-access plans, higher-priced technologies, and cost-shifting from Medicaid and the uninsured to private payers.
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". 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". 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.