He's old school, is Mark Thomas. He believes in left-wing politics and the original tenet of Nye Bevan's mission statement of the National Health Service, upon its inception: ' In place of fear'.

As the NHS has just turned 70, Thomas ponders the implications of an institution so many of us rely on, with particular emphasis on an ageing population. It's a deeply personal project and close to his heart, as his mother was a midwife, working in the Gorbals area of Glasgow.

So it comes as no surprise that he takes a scalpel to a few myths surrounding the NHS, using testimonials from medical professionals such as Tony Blair's Secretary of State for Health, Frank Dobson, and Dr Jackie Applebee, who provides a daily drop in service at Tower Hamlets.

The statistics are troubling: only four in ten people with mental health issues are seen straight away; we're not treating cancer as well as other nations ('we're the Jedward of cancer', he quips) and Britain is thirteenth in the performance league table.

But home truths, as with pills, are better with a little sweetener, and Thomas' scathing delivery is of course hilarious and self-deprecating, musing on his own weight and potential future illnesses.

It's a compassionate and trenchant show, with typically Thomas zingers and some nice theatrical touches (shadow play and a jazz segment during surgery).It's a sobering show – even angry – but Thomas carries it off with aplomb and finesse.

Traverse Theatre, until 26 Aug (not 13, 20), times vary, £20.50–£21.50 (£15–15.50).