During the latter half of the 19th century, health care in the Western world was radically transformed by a series of dramatic advances in the theory and practice of medicine. The discovery that most common infections were caused by biological agents (‘‘germs’’) led to the development of entirely new therapies and curative strategies. That finding also underpinned the development of invasive surgery as a major arm of medical practice, something which only became possible when the need for aseptic conditions was recognised.

A host of other developments during that period helped fuel the medical revolution. Among major advances were the emergence of reliable anaesthetics that prefaced major surgery becoming routine in the metropolis, and the manufacture of improved technological aids to diagnosis, such as microscopes and X-rays. These enabled specific disease- causing agents to be identified and subsequently countered. Within a few decades of the breakthrough in understanding disease causation, many of the epidemic diseases that had plagued mankind throughout recorded history had been largely eradicated from Western society.

Scientific and technological advances in medicine were mirrored in the social sphere both by environmental transformations in individual and group practice – clean houses and streets for example – and by a growing professionalisation of the medical world. Medicine in the West became an organised body of knowledge and practice, with professional journals to disseminate agreed norms and new research. Standardised training and qualifications were instituted and these were recognised and regularised at state level. Medicine became part of the apparatus of the state, which sponsored research and structural improvements in both civil and military spheres. These developments greatly enhanced the formerly low status of the medical profession. It became increasingly dominated by practitioners from the middle and upper classes, which extended its social authority and strengthened its links to the state and political power.

As a result of this process, from around 1870 onwards, medicine in the West became increasingly distinct from the non-Western medical systems with which it had earlier shared numerous concepts, practices, and historical links. It also became almost entirely distinct from its own earlier understandings and practices.