n.
Extent of continuing physical, emotional, mental, and social ability to cope with one's environment.
Good health is harder to define than bad health (which can be equated with presence of disease) because it must convey a more positive concept than mere absence of disease, and there is a variable area between health and disease. A person may be in good physical condition but have a cold or be mentally ill. Someone may appear healthy but have a serious condition (e.g., cancer) that is detectable only by physical examination or diagnostic tests or not even by these.