He was born in Wales at Rackery Farm near Wrexham, Denbighshire, the son of Anne (née Williams), who died in 1823, and Samuel Warren (1781–1862), a Wesleyan Methodist minister, who formed a breakaway group, and in later life was an Anglican priest in Ancoats.

[4] Warren attended the University of Edinburgh to study medicine, in the years 1826 to 1828, where he won prizes and attention, but did not take a degree.

[4][7] The frame story to the series is of "early struggles" of a young medical man, and has been taken to contain embellished autobiographical material.

[8] In the preface to fifth edition (1855) was Warren's statement that "I was six years actively engaged in the practical study of physic".

[11] Proposed bookends are an 1821 story by William Maginn, and one by Samuel Ferguson in 1837, when Warren's series had concluded.