Traditional

Nursing historians face the challenge of determining whether care provided to the sick or injured in antiquity was nursing care. In the fifth century BC, for example, the Hippocratic Collection in places describes skilled care and observation of patients by male "attendants", who may have been early nurses. Around 600 BC in India, it is recorded in Sushruta Samhita, Book 3, Chapter V about the role of nurse as "the different parts or members of the body as mentioned before including the skin, cannot be correctly described by one who is not well versed in anatomy. Hence, any one desirous of acquiring a thorough knowledge of anatomy should prepare a dead body and carefully, observe, by dissecting it, and examine its different parts."

Before the foundation of modern nursing, members of religious orders such as nuns and monks often provided nursing-like care. Examples exist in Christian, Islamic and Buddhist traditions amongst others. Phoebe, mentioned in Romans 16 has been described in many sources as "the first visiting nurse". These traditions were influential in the development of the ethos of modern nursing. The religious roots of modern nursing remain in evidence today in many countries. One example in the United Kingdom is the use of the historical title "sister" to refer to a senior nurse in the past.

During the Reformation of the 16th century, Protestant reformers shut down the monasteries and convents, allowing a few hundred municipal hospices to remain in operation in northern Europe. Those nuns who had been serving as nurses were given pensions or told to get married and stay home. Nursing care went to the inexperienced as traditional caretakers, rooted in the Roman Catholic Church, were removed from their positions. The nursing profession suffered a major setback for approximately 200 years.

19th century

Florence Nightingale laid the foundations of professional nursing after the Crimean War. Her Notes on Nursing (1859) became popular. The Nightingale model of professional education, having set up the first school of nursing that is connected to a continuously operating hospital and medical school, spread widely in Europe and North America after 1870. Nightingale was also a pioneer of the graphical presentation of statistical data.

Other important nurses in the development of the profession include:

• Agnes Hunt from Shropshire was the first orthopedic nurse and was pivotal in the emergence of the orthopedic hospital The Robert Jones & Agnes Hunt Hospital in Oswestry, Shropshire.
• Agnes Jones, who established a nurse training regime at the Brownlow Hill infirmary, Liverpool, in 1865.
• Linda Richards, who established quality nursing schools in the United States and Japan, and was officially the first professionally trained nurse in the US, graduating in 1873 from the New England Hospital for Women and Children in Boston
• Clarissa Harlowe "Clara" Barton, a pioneer American teacher, patent clerk, nurse, and humanitarian, and the founder of the American Red Cross.
• Saint Marianne Cope, a Sister of St Francis who opened and operated some of the first general hospitals in the United States, instituting cleanliness standards which influenced the development of America's modern hospital system.

Catholic orders such as Little Sisters of the Poor, Sisters of Mercy, Sisters of St. Mary, St. Francis Health Services, Inc. and Sisters of Charity built hospitals and provided nursing services during this period. In turn, the modern deaconess movement began in Germany in 1836. Within a half century, there were over 5,000 deaconesses in Europe.

Formal use of nurses in the modern military began in the latter half of the nineteenth century. Nurses saw active duty in the First Boer War, the Egyptian Campaign (1882) and the Sudan Campaign (1883).

20th century

Hospital-based training came to the fore in the early 1900s, with an emphasis on practical experience. The Nightingale-style school began to disappear. Hospitals and physicians saw women in nursing as a source of free or inexpensive labor. Exploitation of nurses was not uncommon by employers, physicians and educational providers.

Many nurses saw active duty in World War I, but the profession was transformed during the second World War. British nurses of the Army Nursing Service were part of every overseas campaign. More nurses volunteered for service in the US Army and Navy than any other occupation. The Nazis had their own Brown Nurses, 40,000 strong. Two dozen German Red Cross nurses were awarded the Iron Cross for heroism under fire.

The modern era saw the development of undergraduate and post-graduate nursing degrees. Advancement of nursing research and a desire for association and organization led to the formation of a wide variety of professional organizations and academic journals. Growing recognition of nursing as a distinct academic discipline was accompanied by an awareness of the need to define the theoretical basis for practice.

In the 19th and early 20th century, nursing was considered a women's profession, just as doctoring was a men's profession. With increasing expectations of workplace equality during the late 20th century, nursing became an officially gender-neutral profession, though in practice the percentage of male nurses remains well below that of female physicians in the early 21st century.

Although nursing practice varies both through its various specialties and countries, these nursing organizations offer the following definitions:

Nursing encompasses autonomous and collaborative care of individuals of all ages, families, groups and communities, sick or well and in all settings. Nursing includes the promotion of health, prevention of illness, and the care of ill, disabled and dying people. Advocacy, promotion of a safe environment, research, participation in shaping health policy and in patient and health systems management, and education are also key nursing roles.

—?International Council of Nurses

The use of clinical judgment in the provision of care to enable people to improve, maintain, or recover health, to cope with health problems, and to achieve the best possible quality of life, whatever their disease or disability, until death.

—?Royal College of Nursing (2003)

Nursing is the protection, promotion, and optimization of health and abilities; prevention of illness and injury; alleviation of suffering through the diagnosis and treatment of human responses; and advocacy in health care for individuals, families, communities, and populations.

—?American Nurses Association

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 (or to peaceful death) that he would perform unaided if he had the necessary strength, will or knowledge.

—?Virginia Avenel Henderson

The authority for the practice of nursing is based upon a social contract that delineates professional rights and responsibilities as well as mechanisms for public accountability. In almost all countries, nursing practice is defined and governed by law, and entrance to the profession is regulated at the national or state level.

The aim of the nursing community worldwide is for its professionals to ensure quality care for all, while maintaining their credentials, code of ethics, standards, and competencies, and continuing their education. There are a number of educational paths to becoming a professional nurse, which vary greatly worldwide; all involve extensive study of nursing theory and practice as well as training in clinical skills.

Nurses care for individuals of all ages and cultural backgrounds who are healthy and ill in a holistic manner based on the individual's physical, emotional, psychological, intellectual, social, and spiritual needs. The profession combines physical science, social science, nursing theory, and technology in caring for those individuals.

To work in the nursing profession, all nurses hold one or more credentials depending on t