UK and Ireland: Medical Records

• The Wellcome Library has pages on "finding medical archives elsewhere" and on "Biography and family history: general resources".
• The archive of the British Medical Journal allow free full text search of articles since 1840 for those who may have written, or been mentioned in, their articles. 
• For explanations of old medical terms see Glossary of Diseases from Genealogy Quest, Medical Conditions - especially old ones from Andrew Billinghurst, Old Disease Names frequently found on Death Certificates from Greene County Museum and Diseases and Medical Terms for Genealogists from Ian Beach Shirley Hornbeck's This And That....Genealogy Tips On Diseases, Medical Terms, Epidemics (archived site).
• John Snow did pioneering work on the causes of cholera. This fascinating website includes the full text of Snow's 1855 publication On the Mode of Communication of Cholera and maps illustrating his work and ideas. See also Cholera Inquiry Commission Report 1854 "into the causes which have led to, or have aggravated, the late outbreak of Cholera in the towns of Newcastle-upon-Tyne, Gateshead and Tynemouth."
• A Chronology of State Medicine, Public Health, Welfare and Related Services in Britain. 1066 - 1999 compiled by Michael D. Warren.
• Public Health, Fifth Report of the Medical Officer of the Privy Council, 1862 from Google Books
• Antiquus Morbus - A Glossary of Archaic Medical Terms, Diseases and Causes of Death (archived copy).
• Records of Dentists, Doctors and Nurses - see Occupations
• Historical details and photographs of nearly 150 English, Welsh and Scottish  County Asylums.
• Hospitals:
  • Hospital Records Database (A Joint Project of the Wellcome Trust and the Public Record Office) "This database provides information on the existence and location of the records of the hospitals in the U.K.".
  • Voluntary Hospitals Database - "provides information on the existence and location of the records of UK hospitals".
  • Historic Hospitals Admissions Record Project (HHARP) - "the home of 19th century children's hospital records".
  • The patients and some hospital staff may be listed in the censuses and senior staff in trade directories.
  • Hospital Records may be listed on the National Register of Archives (NRA).
  • Historic Hospitals - An Architectural Gazetteer, by Harriet Richardson. Provides brief histories, and numerous pictures and maps, of a large number of hospitals in Scotland, and of mental hospitals in Britain and Ireland.
• A History of Epidemics in Britain - by J. Doe.