Strap in for the emotional ride of your life – Kay's new show will have you sobbing and snorting with laughter before the hour's up

Upon enetering the auditorium, we're faced with a big exit sign from the cover of Adam Kay's new book, Undoctored: The Story of a Medic Who Ran Out of Patients, as well as a large heart rate monitor flashing in bright showbiz lights. Beneath them stand three pill bottle podiums – one acting as a lecturn and the other two propping up a keyboard. Like the rest of the audience, we've no clue what's in store tonight. Is it a comedy show? Is it a book reading? All we know for sure is that it's going to be good, judging by the sell-out rate of every show so far in this Edinburgh run.

As we're soon to discover, the next hour will be a bit of an all-rounder. Kay – comedian, screenwriter, author and former junior doctor – brings all of his skills to the table (or pill bottle) and even adds a new one: musician. He's grade eight at piano as it turns out. Is there nothing this man can't do?

This is Going to Hurt, Kay's first book – which was also picked up for a BBC series starring Ben Whishaw – documented his time in medicine. The follow-up instead tackles the reasons why so many doctors leave the industry. When he quit 13 years ago, he explains, he only knew two others who'd done the same. Now there are as many as 10 resigning daily – more than those retiring.

He proceeds to read from Undoctored, which draws from his diaries at the time, much like the first book. These excerpts are interspersed with comedic, piano-led numbers to the tunes of pop hits such as 'Eternal Flame' by The Bangles. And so we learn about Kay's six years in medical school, seven as a qualified doctor and the years that followed. It's both graphic and emotional in turn. In fact, there have even been faintings in previous shows. Staff claim a warm venue, but we'd wager the "worst wank story" (involving a lodged bladder stone) had something to do with it. Or perhaps it was the "degloving" anecdote – and we're not talking about hands…

But in amongst the gore and silly sing-alongs are unimaginably heartbreaking stories that will catch you off guard. Even Kay is spotted wiping a tear as he recounts past traumas. One of the most moving takeaways involves the campaign he's currently pursuing to have trees planted at hospitals in memoriam of the doctors who've taken their own lives on the job. That and a very adorable surprise at the end to counter the heartache. Undoctored is one hell of an emotional rollercoaster, but it's a ride you won't want to miss.

By Danielle Goldstein

Adam Kay: Undoctored runs until Monday 28 August. 7.30pm. £15.50/£17.50, £16.50/£14.50 concs. Edinburgh Festival Fringe, Pleasance Courtyard, EH8 9TJ. He then heads to London, Monday 23 – Saturday 28 October. adamkay.co.uk