Nebennierenrindeninsuffizienz
Greenhow was a Fellow of the Royal Society (1870) and a member of many medical societies. In 1879–1881 he was president of the Clinical Society of London, which he had shared in founding in 1867. He was the author of works on diphtheria, chronic bronchitis, and on Addison's disease, the subject of his Croonian lectures (1875). The lectures became the subject of a second book on Addison's disease, and Greenhow delivered the lecture on Addison's disease at the International Medical Congress of 1881: he had had eleven patients of his own. He had pioneered treatment with iron and effervescing medicine which engineered a remission, and so prolonged life.