 One of the fundamental and most long-standing debates in the philosophy of medicine relates to the basic concepts of health and disease (see  concepts of health and disease).  It may seem obvious what we mean by such statements: people seek treatment from medical professionals when they are feeling unwell, and clinicians treat patients in order to help them restore or maintain their health. But people seek advice and assistance from medical professionals for other reasons, such as pregnancy which cannot be construed as a disease state, and high blood pressure which is asymptomatic. Thus the dividing line between disease and health is notoriously vague, due in part to the wide range of variations present in the human population and to debates over whether many concepts of disease are socially constructed. One of the further complicating factors is that both the concepts of health and disease typically involve both descriptive and evaluatory aspects (Engelhardt 1975), both in common usage among lay persons and members of the medical profession.