define disease and illness
Definition: Illness. Illness refers to the sociocultural context within which disease is experienced. The patient and his/her family label, classify, and explain the sickness episode in such a way that it can be personally and socially meaningful (Kleinman 1978).or many adults, the functional component is a critical factor in defining health or illness--in the absence of symptoms, there is no disease. A world view of many cultural groups integrates physical, emotional, and spiritual well-being, and holds that all three are necessary for optimal health.
A disease is a particular abnormal condition, a disorder of a structure or function, that affects part or all of an organism. The causal study of disease is called pathology.Disease is often construed as a medical condition associated with specific symptoms and signs. It may be caused by factors originally from an external source, such as infectious disease, or it may be caused by internal dysfunctions, such as autoimmune diseases.nfectious. Infectious diseases, also known as transmissible diseases or communicable diseases, comprise clinically evident illness (i.e., characteristic medical signs and/or symptoms of disease) resulting from the infection, presence and growth of pathogenic biological agents in an individual host organism.