Born in Chingford, Essex, the daughter of the curate, she moved with her family to Welsh Bicknor. She graduated from the Royal Free Hospital School of Medicine for Women in 1893. She went on to take the University of London's higher degrees in Medicine and Surgery, becoming the first British woman to obtain the degree of Master of Surgery. Throughout her career, Aldrich-Blake was associated with the Elizabeth Garrett Anderson Hospital, becoming senior surgeon in 1910.
At the Royal Free Hospital, she was the first woman to hold the post of surgical registrar and also acted as an anaesthetist. During the First World War, many of the male surgical staff were deployed on foreign active service and Dr Aldrich-Blake took on increased responsibility for the surgery, becoming consulting surgeon to the hospital. She was the first to perform operations for cancers of the cervix and rectum.
Aldrich-Blake was devoted to training students of the Royal Free Hospital's School of Medicine for Women, her own alma mater. She became Dean of the School in 1914.
Dame Louisa Aldrich-Blake died on 28 December 1925 from undisclosed causes.
The Dame Louisa Brandreth Aldrich-Blake Collection is located in the Royal Free Hospital's Archives Centre. A statue of her is in Tavistock Square, London.
- Staff (30 December 1925). "Distinguished woman surgeon. Death of Dame Louisa Aldrich-Blake". Gloucester Citizen – via The British Newspaper Archive. (Subscription required (. ))
- Staff (8 March 1926). "Dame Louisa Aldrich-Blake's Will". Gloucester Citizen – via The British Newspaper Archive. (Subscription required (. ))
- "Baptism Register for Chingford". Baptism Register for Chingford 1842-1866, WF/C83/2 RBp 2, p96.
- London Gazette Issue 33007, published on 30 December 1924