The document outlines Dorothea Orem's Self-Care Deficit Nursing Theory, which identifies universal self-care requisites and specifies when nursing is needed to help meet a person's self-care needs. The theory also describes three nursing systems - wholly compensatory, partly compensatory, and supportive-educative - that help patients meet their self-care requisites by having the nurse, patient, or both work together. Orem identified five methods nurses can use to help patients: acting for them, doing for them, guiding them, supporting them, and teaching them.