[7] Critchlow decided on a career in neuroscience as a teenager after working as a nursing assistant at St Andrew's Hospital.

[13] In 2008 she returned to Cambridge, where she has been professionally based ever since, apart from a one-year secondment to the British Neuroscience Association in 2010–2011.

She took part in a Rising Stars programme run by the University of Cambridge's Public Engagement team in 2011[14] and, together with the cosmologist Andrew Pontzen, produced a series of Naked Shorts on their research for the award-winning podcast The Naked Scientists.

[20] In 2017 Critchlow was appointed as a Science Outreach Fellow by Magdalene College, Cambridge[11][8][18] She was a judge for the 2018 Wellcome Book Prize.

That same year her second book was published called The Science of Fate and made it onto the Sunday Times Bestseller list.