Chronic diseases are illnesses that characteristically have a slow, progressive onset and a long duration. Chronic diseases impact every aspect of the individual's and family's life and usually result from repeated or prolonged exposure to an environment or substance that does not support the normal structure and functioning of the body. Chronic diseases are those illnesses that are part of a person's life, with little or no chance for full recovery. In acute disease, treatments focus on returning the individual to full health. With chronic disease, the medical focus is to limit the progression of the disease or to delay any secondary complication that might arise because of the disease. The body's normal structure and function work like a well-coordinated machine, with each part vital to the whole. The structure and function of the human body of a person with a chronic disease, on both the cellular and systemic levels, ...