The document discusses several theories relevant to community health nursing. It describes Florence Nightingale's environmental theory which views nursing as altering the patient's environment to promote healing. It also outlines Dorothea Orem's self-care theory, which posits that individuals should be self-reliant in caring for themselves and others. Orem's theory identifies universal, developmental, and health-derived self-care requisites. Nursing is needed when self-care capabilities do not meet the therapeutic self-care demands. The document provides overviews of several other theories used in community health nursing.