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'.
The UK's National Health Service (NHS) is a publicly funded healthcare system that provides coverage to everyone normally resident in the UK. It is not strictly an insurance system because (a) there are no premiums collected, (b) costs are not charged at the patient level and (c) costs are not pre-paid from a pool. However, it does achieve the main aim of insurance which is to spread financial risk arising from ill-health. The costs of running the NHS (est. £104 billion in 2007-8) are met directly from general taxation. The NHS provides the majority of health care in the UK, including primary care, in-patient care, long-term health care, ophthalmology, and dentistry.
Hospital and medical expense policies were introduced during the first half of the 20th century. During the 1920s, individual hospitals began offering services to individuals on a pre-paid basis, eventually leading to the development of Blue Cross organizations. The predecessors of today's Health Maintenance Organizations (HMOs) originated beginning in 1929, through the 1930s and on during World War II.
Coverage limits: Some health insurance policies only pay for health care up to a certain dollar amount. The insured person may be expected to pay any charges in excess of the health plan's maximum payment for a specific service. In addition, some insurance company schemes have annual or lifetime coverage maxima. In these cases, the health plan will stop payment when they reach the benefit maximum, and the policy-holder must pay all remaining costs.
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.