There are seven components of wellness: physical, intellectual, social, occupational, emotional, spiritual, and environmental. Illness refers to a diminished state of physical, emotional, intellectual, social, developmental, or spiritual functioning and is not synonymous with disease. There are four levels of prevention: primary prevention aims to prevent health problems, secondary prevention uses early detection and screening, tertiary prevention treats existing health problems to prevent further progression, and rehabilitation aims to prevent further deterioration and loss of function. Healthy People 2020 is a national initiative with the vision of all people living long, healthy lives through overarching goals like attaining quality lives free of preventable illness and achieving health equity.