Nursing Theories & Theorists: The Definitive Guide for Nurses

Nursing theory is the reason the job is a profession and not a checklist. Before theory, nurses carried out physician orders and changed dressings with no framework for why. Theory gave nursing its own body of knowledge, defined the work that no other discipline does, and built the language you use to justify an intervention at the bedside. This guide covers what a nursing theory is, why it matters, how theories are classified, and a working summary of the major theorists.

What Nursing Theories Are

Nursing theories are organized bodies of knowledge that define what nursing is, what nurses do, and why. They frame nursing as its own discipline, separate from medicine, with its own science and its own body of knowledge driving how care is delivered. Identifying and developing that knowledge through concepts and theories is what separates nursing from the task list medicine used to hand it.

Defining Terms

A handful of terms carry the weight in theory work:

• Philosophy. Beliefs and values that define a way of thinking, shared and understood by a group or discipline.
• Theory. A belief, policy, or procedure proposed or followed as the basis of action. A logical group of general propositions used as principles of explanation, used to describe, predict, or control phenomena.
• Concept. The building blocks of theories. Concepts are the vehicles of thought that carry images.
• Models. Representations of how concepts interact and pattern. They give an overview of the theory's thinking and show how it moves into practice.
• Conceptual framework. A group of related ideas, statements, or concepts. Used interchangeably with conceptual model and grand theories.
• Proposition. A statement describing the relationship between concepts.
• Domain. The perspective or territory of a profession or discipline.
• Process. Organized steps, changes, or functions intended to bring about a desired result.
• Paradigm. A pattern of shared understanding and assumptions about reality, a worldview or widely accepted value system.
• Metaparadigm. The most general statement of a discipline, the framework within which more restricted conceptual models develop. In nursing, the theoretical work centers on four concepts: person, environment, health, and nursing.

History of Nursing Theories

The first nursing theories appeared in the late 1800s, when nursing education came into focus. By the 1950s, nursing scholars agreed the field needed to validate itself through its own scientifically tested body of knowledge. The chronology:

• 1860, Florence Nightingale defined nursing in her Environmental Theory as "the act of using the patient's environment to assist him in his recovery."
• 1952, Hildegard Peplau introduced the Theory of Interpersonal Relations, making the nurse-client relationship the foundation of practice.
• 1955, Virginia Henderson framed the nurse's role as helping sick or healthy individuals gain independence in meeting 14 fundamental needs (the Nursing Need Theory).
• 1960, Faye Abdellah published "Typology of 21 Nursing Problems," shifting nursing from a disease-centered to a patient-centered approach.
• 1962, Ida Jean Orlando emphasized the reciprocal patient-nurse relationship and defined nursing's function as finding and meeting the patient's immediate need for help.
• 1968, Dorothy Johnson pioneered the Behavioral System Model, fostering efficient behavioral functioning to prevent illness.
• 1970, Martha Rogers viewed nursing as both science and art, a way to see the unitary human being as integral with the universe.
• 1971, Dorothea Orem held that nursing care is required when the client cannot meet biological, psychological, developmental, or social needs.
• 1971, Imogene King's Theory of Goal Attainment placed the nurse within the patient's environment, with the relationship aimed at meeting health goals.
• 1972, Betty Neuman held that many needs exist and each can disrupt client stability, making stress reduction the goal of the system model.
• 1979, Sr. Callista Roy viewed the individual as interrelated systems maintaining balance among various stimuli.
• 1979, Jean Watson developed the philosophy of caring, joining the humanistic side of nursing to scientific knowledge and practice.

The Nursing Metaparadigm

Four concepts run through nursing theory and define it: person, environment, health, and nursing. Together they are the metaparadigm for nursing.

Person

The recipient of nursing care, also called client or human being. Includes individuals, patients, groups, families, and communities.

Environment

The internal and external surroundings that affect the client, defined broadly to include physical setting, families, friends, significant others, and where the patient goes for care. Covers all positive and negative conditions acting on the patient.

Health

The degree of wellness or well-being the client experiences. It means different things to different patients, settings, and providers.

Nursing

The attributes, characteristics, and actions through which the nurse delivers care on behalf of or alongside the client. Nursing scholars disagree on an exact definition, but the shared goal of nursing theory is to improve patient care.

Metaparadigm Across Different Theorists

Every theorist defines these four concepts differently, shaped by their orientation, experience, and view of nursing. The person stays the main focus, but each theorist's take is unique to their theory.

THEORIST (Theory)	PERSON	HEALTH	NURSING	ENVIRONMENT
NIGHTINGALE (Environmental Theory)	Human beings were not explicitly defined by Nightingale specifically.	Nightingale (1859/1992) did not define health specifically.	“What nursing has to do… is to put the patient in the best condition for nature to act upon him” (Nightingale, 1859/1992)	Nightingale’s writings reflect a community health model in which all that surrounds human beings is considered in relation to their state of health.
OREM (Self-care Deficit Theory)	Humans are defined as “men, women, and children cared for either singly or as social units,” and are the “material object” of nurses and others who provide direct care.	Health is “being structurally and functionally whole or sound.”	Nursing is an art through which the practitioner of nursing gives specialized assistance to persons with disabilities which makes more than ordinary assistance necessary to meet needs for self-care .	The environment has physical, chemical and biological features. It includes the family, culture, and community.
HENDERSON (Need Theory)	Individuals have basic needs that are component of health and require assistance to achieve health and independence or a peaceful death .	Health was taken to mean balance in all realms of human life.	“The unique function of the nurse is to assist the individual, sick or well, in the performance of those activities contributing to health or its recovery that he would perform unaided if he had the necessary strength, will or knowledge. And to do 1 this in such a way as to help him gain independence as rapidly as possible.”	No explicit definition of the environment, though she stated that: “maintaining a supportive environment conducive for health is one of the elements of her 14 activities for client assistance.”
PEPLAU (Interpersonal Relations Theory)	An organism that “strives in its own way to reduce tension generated by needs.”	Health is defined as “a word symbol that implies forward movement of personality and other ongoing human processes in the direction of creative, constructive, productive, personal, and community living.”	Hildegard Peplau considers nursing to be a “significant, therapeutic, interpersonal process.”	Although Peplau does not directly address society/environment, she does encourage the nurse to consider the patient’s culture and mores when the patient adjusts to hospital routine.
ROGERS (Science of Unitary Human Beings)	A person is defined as an indivisible, pan-dimensional energy field identified by a pattern, and manifesting characteristics specific to the whole, and that can’t be predicted from knowledge of the parts.	Rogers defines health as an expression of the life process	Nursing aims to assist people in achieving their maximum health potential.	It is the study of unitary, irreducible, indivisible human and environmental fields: people and their world.
KING (Goal Attainment)	Individuals are social beings who are rational and sentient. Humans communicate their thoughts, actions, customs, and beliefs through language.	Health is a dynamic life experience of a human being, which implies continuous adjustment to stressors in the internal and external environment through optimum use of one’s resources to achieve maximum potential for daily living.	Nursing is a process of action, reaction, and interaction whereby nurse and client share information about their perceptions in the nursing situation.	Environment is the background for human interactions. It is both external to, and internal to, the individual.
WATSON	Human being is a valued person to be cared for, respected, nurtured, understood, and assisted; in general a philosophical view of a person as a fully functional integrated self.	Health is the unity and harmony within the mind, body, and soul; health is associated with the degree of congruence between the self as perceived and the self as experienced.	Nursing is a human science of persons and human health-illness experiences that are mediated by professional, personal, scientific, esthetic, and ethical human care transactions.	Society provides the values that determine how one should behave and what goals one should strive toward.
ROY (Adaptation)	A holistic, adaptive system interacting with the environment; described as a whole with parts functioning as a unity.	Health is a state and a process of being and becoming integrated and whole. It is the reflection of adaptation (survival, growth, reproduction, and mastery).	The goal of nursing is to promote adaptation for individuals and groups in the four adaptive modes (physiologic, self-concept, role function, interdependence).	All conditions, circumstances, and influences surrounding and affecting the development and behavior of persons and groups. Includes focal, contextual, and residual stimuli.
NEUMAN (Systems Model)	An open client system consisting of a basic structure of energy resources. The person is a multidimensional being with physiological, psychological, sociocultural, developmental, and spiritual variables.	Equated with wellness; the condition in which all parts and subparts (variables) are in harmony with the whole of the client.	Concerned with the whole person; a unique profession aimed at reduction of stressors through primary, secondary, and tertiary prevention interventions.	The totality of internal and external forces which surround a person and with which they interact at any given time. Includes the “created environment” unconsciously developed by the client.
LEININGER (Transcultural Nursing)	Humans are believed to be caring and capable of being concerned about others’ needs, well-being, and survival.	A state of well-being that is culturally defined, valued, and practiced. It reflects the ability of individuals to perform their daily role activities.	A learned humanistic and scientific profession and discipline which is focused on human care phenomena and activities to assist, support, facilitate, or enable individuals or groups to maintain or regain their well-being.	The totality of an event, situation, or particular experience that gives meaning to human expressions, interpretations, and social interactions in particular physical, ecological, sociopolitical, and/or cultural settings.
JOHNSON (Behavioral System)	A behavioral system within seven interrelated subsystems (attachment, dependency, ingestive, eliminative, sexual, aggressive, achievement)	An efficient and effective behavioral functioning; a state of balance and stability in the behavioral system.	Nursing is an external regulatory force which acts to presever the organization and integration of the patient’s behaviors at the optimum level.	Consists of all the factors that are not part of the individual’s behavioral system but influence the system.
ABDELLAH (21 Nursing Problems)	The recipient of nursing care who has physical, emotional, and sociological needs.	A state mutually exclusive of illness; described as a state when the individual has no unmet needs and no anticipated impairments.	A comprehensive service based on an art and science that aims to help people, sick or well, cope with their health needs. Focuses on 21 nursing problems.	The home or community from which the patient comes; included in “ planning for continuity of care”. Abdellah discusses the therapeutic environment as part of the remedial care needs.

Components of Nursing Theories

To be a theory, it has to contain concepts, definitions, relational statements, and assumptions that explain a phenomenon, and it has to show how those parts relate.

Phenomenon

A term describing an idea or response about an event, situation, process, or group of events. Phenomena may be temporary or permanent. Nursing theories focus on the phenomena of nursing.

Concepts

Interrelated concepts define a theory. They label and describe a phenomenon, setting structure and boundaries for the ideas generated about it. Concepts may be abstract (constructed independently of a specific time or place) or concrete (directly experienced and tied to a particular time or place).

Definitions

Definitions convey the general meaning of a theory's concepts. Theoretical definitions describe a concept from the theorist's perspective; operational definitions state how the concept is measured.

Relational Statements

These define the relationships between two or more concepts. They are the chains linking concepts to one another.

Assumptions

Statements accepted as truths, grounded in values and beliefs. They explain the nature, purpose, relationships, and structure of a theory.

Why Nursing Theories Matter

Nursing theory is the basis of practice today. It guides knowledge development and directs education, research, and practice. Historically, nursing was a task-oriented occupation under the direction of the medical profession, not an academic discipline. Theory changed that:

• It sets the foundation of practice by describing nursing explicitly, which gives nurses a clear sense of purpose and role.
• It supplies the rationale behind interventions, the knowledge base for acting and responding appropriately in care situations (Brown, 1964).
• It gives nurses a professional identity that patients, managers, and other clinicians can recognize, making the unique contribution of nursing visible (Draper, 1990).
• It pushes nurses to examine assumptions and question nursing values, which sharpens the definition of nursing and grows the knowledge base.
• It defines, predicts, and demonstrates nursing phenomena (Chinn and Jacobs, 1978).
• It guides research, informs evidence-based practice, and provides a common language for nurses.
• It serves as the basis for nursing education and training programs, with theory, education, research, and practice each influencing the others (Fitzpatrick and Whall, 2005).

Purposes of Nursing Theories

The primary purpose of theory in nursing is to improve practice by positively affecting patients' health and quality of life. Theory defines and describes nursing care, guides practice, and provides the basis for clinical decision-making. It also drove nursing's recognition as an academic discipline, a research field, and a profession.

In Academic Discipline

Early nursing programs took the major concepts from one or two models, organized them, and built an entire curriculum around that framework, carrying the model's language into course objectives and clinical performance criteria. The "curriculum revolution" of the 1970s and 80s shows this clearly. Universities like UCSF moved away from vocational, task-based training by adopting frameworks like Roy's Adaptation Model or Orem's Self-Care Model to structure whole programs. Students learned a nursing language separate from medicine and were taught to assess why a patient was not healing, not just how to change a dressing, which helped elevate nursing into a respected discipline.

In Research

Theory is fundamental to research, providing the framework that gives a study perspective and guidance, and creating phenomena to test. A continuous loop among theory, practice, and research closes the perceived gap between theory and practice. Katharine Kolcaba's Comfort Theory is a working example. In the 1990s she saw that standard metrics like "pain management" missed patients' real needs, such as relief from fear or loneliness. By defining comfort as a measurable variable, she let researchers test and validate holistic interventions, such as heated blankets or hand massages in post-anesthesia units, and show those comfort measures improved recovery.

In the Profession

Clinical practice generates the research questions and knowledge that feed theory. At the bedside, theory's main contribution is forcing reflection, questioning what nurses do in settings where practice is often subordinate to institutional tradition. Patricia Benner's Novice to Expert theory protected new nurses from that pressure. New graduates were once expected to perform like veterans immediately, which drove burnout. Benner's framework pushed hospitals to build clinical ladders and residency programs and to recognize that a novice relies on rules while an expert relies on intuition. Theory also drives reflection in daily care, as when a nurse uses Orem's theory to assist an arthritic patient only with socks rather than dressing them fully, consciously preserving the patient's independence instead of just finishing the task.

Classification of Nursing Theories

Theories are categorized by function, level of abstraction, or goal orientation.

By Abstraction

Grand Nursing Theories

Abstract, broad in scope, and complex, requiring further research to clarify. They do not direct specific interventions but provide a general framework and nursing ideas, and they address the metaparadigm components of person, nursing, health, and environment. Grand theorists built their work from their own experience and era, which explains the wide variation among them.

Middle-Range Nursing Theories

More limited in scope than grand theories, with concepts and propositions at a lower level of abstraction, addressing a specific phenomenon. Scholars proposed this level because grand theories are hard to test. Most build on a grand theorist's work but can also come from research, practice, or other disciplines.

Practice-Level Nursing Theories

Situation-specific and narrow, focused on a specific patient population at a specific time. They provide frameworks for interventions and predict outcomes, and they have a more direct effect on practice than abstract theories. They connect to concepts from middle-range and grand theories.

By Goal Orientation

Theories are either descriptive or prescriptive.

Descriptive Theories

The first level of theory development. They describe a phenomenon and identify its properties and components without trying to change a situation. Two types: factor-isolating theory (also called category-formulating or labeling theory, which describes the properties and dimensions of phenomena) and explanatory theory (which describes and explains how phenomena relate to one another).

Prescriptive Theories

Address the interventions for a phenomenon, guide practice change, and predict consequences. They include propositions that call for change and are used to anticipate the outcomes of nursing interventions.

Other Classifications

According to Meleis. Afaf Ibrahim Meleis (2011), in Theoretical Nursing: Development and Progress, organizes the major theories by their philosophical underpinnings:

• Needs-Based Theories. The first group to give nursing care a conceptual order, built on helping individuals meet physical and mental needs. Orem, Henderson, and Abdellah fall here. Criticized for leaning too much on the medical model and placing the patient in a dependent position.
• Interaction Theories. Center on establishing and maintaining relationships and on how nursing affects patients and their interaction with environment, people, and situations. King, Orlando, and Travelbee belong here.
• Outcome Theories. Describe the nurse as directing care using knowledge of human physiological and behavioral systems. Johnson, Levine, Rogers, and Roy belong here.

According to Alligood. Raile Alligood (2017), in Nursing Theorists and Their Work, uses four headings:

• Nursing Philosophy. The most abstract type, setting forth the meaning of nursing phenomena through analysis and reasoning. Works of Nightingale, Watson, Ray, and Benner.
• Nursing Conceptual Models. Comprehensive theories that address the metaparadigm and the relationships within it. Models of Levine, Rogers, Roy, King, and Orem.
• Grand Nursing Theories. Derived from philosophies, conceptual models, and other grand theories, less specific than middle-range theories. Works of Levine, Rogers, Orem, and King.
• Middle-Range Theories. Precise, answering specific practice questions within a model's perspective. Examples from Mercer, Reed, Mishel, and Barker.

List of Nursing Theories and Theorists

A working summary of the major published works in nursing theory, in roughly chronological order.

Florence Nightingale

Founder of modern nursing and pioneer of the Environmental Theory. Defined nursing as "the act of using the environment of the patient to assist him in his recovery," which "ought to signify the proper use of fresh air, light, warmth, cleanliness, quiet, and the proper selection and administration of diet, all at the least expense of vital power to the patient." Identified five environmental factors: fresh air, pure water, efficient drainage, cleanliness or sanitation, and light or direct sunlight.

Hildegard E. Peplau

Pioneered the Theory of Interpersonal Relations, defining nursing as "an interpersonal process of therapeutic interactions between an individual who is sick or in need of health services and a nurse specially educated to recognize, respond to the need for help." Influenced by Harry Stack Sullivan, Percival Symonds, Abraham Maslow, and Neal Elgar Miller. Helps clinicians develop more therapeutic interventions at the bedside.

Virginia Henderson

Developed the Nursing Need Theory, focused on increasing the patient's independence to speed recovery and on the basic human needs nurses help meet. "The nurse is expected to carry out a physician's therapeutic plan, but individualized care is the result of the nurse's creativity in planning for care."

Faye Glenn Abdellah

Developed the 21 Nursing Problems Theory. "Nursing is based on an art and science that molds the attitudes, intellectual competencies, and technical skills of the individual nurse into the desire and ability to help people, sick or well, cope with their health needs." Moved nursing from disease-centered to patient-centered and brought families and the elderly into care. Built for hospitals but applicable to community health nursing.

Ernestine Wiedenbach

Developed The Helping Art of Clinical Nursing model, reflecting her nurse-midwife experience: "People may differ in their concept of nursing, but few would disagree that nursing is nurturing or caring for someone in a motherly fashion." Specified four elements of clinical nursing: philosophy, purpose, practice, and art, centered on meeting the patient's perceived need for help.

Lydia E. Hall

Developed the Care, Cure, Core Theory, the "Three Cs of Lydia Hall." Defined nursing as "participation in care, core and cure aspects of patient care, where CARE is the sole function of nurses, whereas the CORE and CURE are shared with other members of the health team." The care circle is bodily care, the core is the patient receiving care, and the cure is medications and treatments.

Joyce Travelbee

In her Human-to-Human Relationship Model, nursing's purpose is to help an individual, family, or community prevent or cope with illness and suffering and, if necessary, find meaning in it, with the ultimate goal being hope. Nursing is accomplished through human-to-human relationships. Extended the interpersonal theories of Peplau and Orlando.

Kathryn E. Barnard

Developed the Child Health Assessment Model, focused on improving the health of infants and their families. Her findings on parent-child interaction as a predictor of cognitive development shaped public policy. Founder of the Nursing Child Assessment Satellite Training Project (NCAST). Borrows from psychology and human development and changed how providers assess children in light of the parent-child relationship.

Evelyn Adam

Focused on developing models and theories on the concept of nursing, covering the profession's goal, the beneficiary, the professional's role and intervention, the source of the beneficiary's difficulty, and the consequences. A clean example of expanding a unique nursing base.

Nancy Roper, Winifred Logan, and Alison J. Tierney

Developed A Model for Nursing Based on a Model of Living, a simple theory built to actually help bedside nurses. The trio collaborated on the fourth edition of The Elements of Nursing and the monograph The Roper-Logan-Tierney Model of Nursing: Based on Activities of Daily Living. Covers maintaining a safe environment, communicating, breathing, eating and drinking, eliminating, personal cleansing and dressing, controlling body temperature, mobilizing, working and playing, expressing sexuality, sleeping, and dying.

Ida Jean Orlando

Developed the Nursing Process Theory. "Patients have their own meanings and interpretations of situations, and therefore nurses must validate their inferences and analyses with patients before drawing conclusions." People become patients when they have needs for help they cannot meet alone, whether from physical limitations, negative reactions to an environment, or an inability to communicate the need. The nurse's role is to find and meet the immediate need.

Jean Watson

Pioneered the Philosophy and Theory of Transpersonal Caring. "Nursing is concerned with promoting health, preventing illness, caring for the sick, and restoring health." Caring is central to practice and promotes health better than a medical cure alone.

Marilyn Anne Ray

Developed the Theory of Bureaucratic Caring. "Improved patient safety, infection control, reduction in medication errors, and overall quality of care in complex bureaucratic health care systems cannot occur without knowledge and understanding of complex organizations, such as the political and economic systems, and spiritual-ethical caring, compassion and right action for all patients and professionals." Pushes nurses to view health care organizations and nursing phenomena holistically, as wholes and parts of a system.

Patricia Benner

Authored Caring, Clinical Wisdom, and Ethics in Nursing Practice. "The nurse-patient relationship is not a uniform, professionalized blueprint but rather a kaleidoscope of intimacy and distance in some of the most dramatic, poignant, and mundane moments of life." Works to reestablish caring practices when nurses are rewarded mainly for efficiency and measurable outcomes.

Kari Martinsen

Developed a Philosophy of Caring. "Nursing is founded on caring for life, on neighborly love, […] At the same time, the nurse must be professionally educated." Caring, solidarity, and moral practice are unavoidable realities, and human beings are ones for whom we may have administrative responsibility.

Katie Eriksson

Developed the Theory of Carative Caring. "Caritative nursing means that we take 'caritas' into use when caring for the human being in health and suffering […] Caritative caring is a manifestation of the love that 'just exists' […] Caring communion, true caring, occurs when the one caring in a spirit of caritas alleviates the suffering of the patient." The ultimate goal of caring is to lighten suffering and serve life and health. Widely used in the Nordic countries.

Myra Estrin Levine

In the Conservation Model, "Nursing is human interaction." Provides a framework for teaching beginning students. Logically congruent, internally and externally consistent, with breadth and depth, and understood by professionals and consumers of health care alike.

Martha E. Rogers

In the Science of Unitary Human Beings, defined nursing as "an art and science that is humanistic and humanitarian." The science is the nursing knowledge from research; the art is using that knowledge creatively to better the patient's life. A patient cannot be separated from their environment when addressing health and treatment.

Dorothea E. Orem

In the Self-Care Theory, defined nursing as "the act of assisting others in the provision and management of self-care to maintain or improve human functioning at the home level of effectiveness." Focuses on each individual's ability to perform self-care. Composed of three interrelated theories: self-care, self-care deficit, and nursing systems (further classified as wholly compensatory, partially compensatory, and supportive-educative).

Imogene M. King

Developed the Conceptual System and Middle-Range Theory of Goal Attainment. "Nursing is a process of action, reaction and interaction by which nurse and client share information about their perception in a nursing situation," a process in which each perceives the other and, through communication, they set goals, explore means, and agree on how to achieve them. The nurse and patient work hand-in-hand to meet health goals.

Betty Neuman

In Neuman's Systems Model, defined nursing as "a unique profession in that is concerned with all of the variables affecting an individual's response to stress." The focus is the client as a system (individual, family, group, or community) and the client's response to stressors. The client system includes five variables (physiological, psychological, sociocultural, developmental, and spiritual), conceptualized as an inner core of basic energy resources surrounded by lines of resistance, a normal defense line, and a flexible line of defense.

Sister Callista Roy

In the Adaptation Model, defined nursing as "a health care profession that focuses on human life processes and patterns and emphasizes the promotion of health for individuals, families, groups, and society as a whole." Views the individual as interrelated systems striving to balance various stimuli. Inspired many middle-range theories and adaptation instruments.

Dorothy E. Johnson

The Behavioral System Model defined nursing as "an external regulatory force that acts to preserve the organization and integrate the patients' behaviors at an optimum level under those conditions in which the behavior constitutes a threat to the physical or social health or in which illness is found." Fosters efficient behavioral functioning to prevent illness and stresses research-based knowledge about nursing's effect on patients. Describes the person as a behavioral system with seven subsystems: achievement, attachment-affiliative, aggressive-protective, dependency, ingestive, eliminative, and sexual.

Anne Boykin and Savina O. Schoenhofer

Developed The Theory of Nursing as Caring: A Model for Transforming Practice. Nursing is an "exquisitely interwoven" unity of the discipline and profession, with its focus and aim being "nurturing persons living to care and growing in caring." Caring is "an altruistic, active expression of love, and is the intentional and embodied recognition of value and connectedness."

Afaf Ibrahim Meleis

Developed Transitions Theory, which grew from observing how people handle changes in health, well-being, and self-care. Types of transitions include developmental, health and illness, situational, and organizational. The nurse's role is to facilitate healthy transitions for patients, families, and communities.

Nola J. Pender

Developed the Health Promotion Model, describing the interaction between nurse and consumer within the health promotion environment. Focuses on three areas: individual characteristics and experiences, behavior-specific cognitions and affect, and behavioral outcomes. Describes the multidimensional nature of people as they interact with their environment to pursue health.

Madeleine M. Leininger

Developed the Culture Care Theory of Diversity and Universality. Defined transcultural nursing as "a substantive area of study and practice focused on comparative cultural care (caring) values, beliefs, and practices of individuals or groups of similar or different cultures to provide culture-specific and universal nursing care practices in promoting health or well-being or to help people to face unfavorable human conditions, illness, or death in culturally meaningful ways." Centers on the fact that cultures hold different caring behaviors and different health and illness values.

Margaret A. Newman

Developed Health as Expanding Consciousness. "Nursing is the process of recognizing the patient in relation to the environment, and it is the process of the understanding of consciousness." The theory was stimulated by concern for those for whom health as the absence of disease or disability is not possible. Nursing is a connection between nurse and patient in which both grow toward higher levels of consciousness.

Rosemarie Rizzo Parse

Developed the Human Becoming Theory. "Nursing is a science, and the performing art of nursing is practiced in relationships with persons (individuals, groups, and communities) in their processes of becoming." A person is more than the sum of the parts, inseparable from the environment, and nursing is a human science and art that uses an abstract body of knowledge to help people. Centered on three themes: meaning, rhythmicity, and transcendence.

Helen C. Erickson, Evelyn M. Tomlin, and Mary Ann P. Swain

Developed Modeling and Role-Modeling. "Nursing is the holistic helping of persons with their self-care activities in relation to their health... The goal is to achieve a state of perceived optimum health and contentment." Modeling lets nurses understand and appreciate the client's unique perspective; role-modeling is planning and implementing interventions unique to that client.

Gladys L. Husted and James H. Husted

Created the Symphonological Bioethical Theory. "Symphonology (from 'symphonia,' a Greek word meaning agreement) is a system of ethics based on the terms and preconditions of an agreement." Nursing cannot occur without both nurse and patient: "A nurse takes no actions that are not interactions." Founded on human rights and the agreement of non-aggression among rational people.

Ramona T. Mercer

Developed Maternal Role Attainment, Becoming a Mother. "Nursing is a dynamic profession with three major foci: health promotion and prevention of illness, providing care for those who need professional assistance to achieve their optimal level of health and functioning, and research to enhance the knowledge base for providing excellent nursing care." Maternal role attainment is an interactional, developmental process over time, through which the mother becomes attached to her infant, gains competence in caretaking, and expresses pleasure and gratification (Mercer, 1986). Supports nontraditional mothers in adopting a strong maternal identity.

Merle H. Mishel

Developed the Uncertainty in Illness Theory, a structure for viewing acute and chronic illness and organizing interventions to promote adjustment. Describes how individuals form meaning from illness-related situations. The original theory organized concepts in a linear model around three themes: antecedents of uncertainty, the process of uncertainty appraisal, and coping with uncertainty.

Pamela G. Reed

Developed the Self-Transcendence Theory. Self-transcendence is the fluctuation of perceived boundaries that extends the person beyond immediate and constricted views of self and the world (Reed, 1997). Built on three concepts: vulnerability, self-transcendence, and well-being. Gives insight into the developmental nature of humans in health circumstances tied to nursing care.

Carolyn L. Wiener and Marylin J. Dodd

Developed the Theory of Illness Trajectory. "The uncertainty surrounding a chronic illness like cancer is the uncertainty of life writ large. By listening to those who are tolerating this exaggerated uncertainty, we can learn much about the trajectory of living." Provides a framework for understanding how cancer patients face uncertainty manifested as loss of control and how patients and families work to reduce it through a dynamic flow of illness events, treatment situations, and care players.

Georgene Gaskill Eakes, Mary Lermann Burke, and Margaret A. Hainsworth

Developed the Theory of Chronic Sorrow. "Chronic sorrow is the presence of pervasive grief-related feelings that have been found to occur periodically throughout the lives of individuals with chronic health conditions, their family caregivers and the bereaved." This middle-range theory frames chronic sorrow as a normal response to the ongoing disparity created by loss.

Phil Barker

Developed Barker's Tidal Model of Mental Health Recovery, widely used in mental health nursing. Focused on fundamental care processes, universally applicable, and a practical guide for psychiatry. Built on values about relating to people in moments of distress, expressed in the Ten Commitments: value the voice, respect the language, develop genuine curiosity, become the apprentice, use the available toolkit, craft the step beyond, give the gift of time, reveal personal wisdom, know that change is constant, and be transparent.

Katharine Kolcaba

Developed the Theory of Comfort. "Comfort is an antidote to the stressors inherent in health care situations today, and when comfort is enhanced, patients and families are strengthened for the tasks ahead. Also, nurses feel more satisfied with the care they are giving." Patient comfort exists in three forms (relief, ease, and transcendence) across four contexts (physical, psychospiritual, environmental, and sociocultural). As comfort needs change, so do the nurse's interventions.

Cheryl Tatano Beck

Developed the Postpartum Depression Theory. "The birth of a baby is an occasion for joy, or so the saying goes […] But for some women, joy is not an option." Describes nursing as a caring profession with obligations to patients, students, and each other. Provides evidence to understand and prevent postpartum depression.

Kristen M. Swanson

Developed the Theory of Caring. "Caring is a nurturing way of relating to a valued other toward whom one feels a personal sense of commitment and responsibility." Defines nursing as informed caring for the well-being of others and gives a structure for improving practice, education, and research while returning the discipline to its caring-healing roots.

Cornelia M. Ruland and Shirley M. Moore

Developed the Peaceful End-of-Life Theory. The focus is not death itself but providing a peaceful, meaningful life in the time that remains for patients and their loved ones, reflecting the complexity of caring for terminally ill patients.

Wanda de Aguiar Horta

Known as Wanda Horta, she introduced the concepts of nursing accepted in Brazil and wrote the book Nursing Process, which gives a holistic view of the patient across nursing practice. Her work, recognized across teaching institutions, is the Theory of Basic Human Needs, based on Maslow's Theory of Human Motivation and its hierarchy of Basic Human Needs (BHN). She classified basic human needs into three dimensions (psychobiological, psychosocial, and psychospiritual) and tied together the concepts of human being, environment, and nursing. Horta described nursing as part of a healthcare team functioning through a scientific method she called the nursing process, defined as the dynamics of systematic, interrelated actions to assist human beings, characterized by six phases: nursing history, nursing diagnosis, assistance plan, care plan or nursing prescription, evolution, and prognosis.