What’s the difference between a doctor and a nurse? Our cover picture this week suggests that the differences are becoming harder to spot, and in this issue Rebecca Coombes explores the shifting and increasingly overlapping territories of the two professions (doi:10.1136/bmj.a1522). It’s easy to understand why the nurse’s role is expanding into traditionally medical areas of diagnosis and treatment: there’s the lower direct cost of employing nurses and the fact that they have more time to spend with patients.

But it’s not all plain sailing. There’s confusion over titles, a lack of nationally agreed standards on what training …