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.
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.
Insurance companies are not allowed to have co-payments, caps, or deductibles, or to deny coverage to any person applying for a policy, or to charge anything other than their nationally set and published standard premiums. Therefore, every person buying insurance will pay the same price as everyone else buying the same policy, and every person will get at least the minimum level of coverage.
In 2013 a state funded private care insurance was introduced ("Private Pflegeversicherung"). Insurance contracts that fit certain criteria are subsidised with 60 Euro per year. It is expected that the number of contracts will grow from 400,000 by end of 2013 to over a million within the next few years. These contracts have been criticized by consumer rights foundations.
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, and worldwide by six years since 1990.
Germany has a universal multi-payer system with two main types of health insurance: law enforced health insurance (or public health insurance) (Gesetzliche Krankenversicherung (GKV)) and private insurance (Private Krankenversicherung (PKV)). Both systems struggle with the increasing cost of medical treatment and the changing demography. About 87.5% of the persons with health insurance are members of the public system, while 12.5% are covered by private insurance (as of 2006). There are many differences between the public health insurance and private insurance. In general the benefits and costs in the private insurance are better for young people without family. There are hard salary requirements to join the private insurance because it is getting more expensive advanced in years.
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." This definition has been subject to controversy, as it may have limited value for implementation. Health may be defined as the ability to adapt and manage physical, mental and social challenges throughout life.