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. (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.)
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.
Currently 85% of the population is covered by a basic health insurance plan provided by statute, which provides a standard level of coverage. The remainder opt for private health insurance, which frequently offers additional benefits. According to the World Health Organization, Germany's health care system was 77% government-funded and 23% privately funded as of 2004.
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.