Dr Brian Keighley said the ongoing "crisis management" of an under-resourced NHS could not continue.
He warned that, irrespective of the outcome of the independence referendum, politicians and the public must face up to difficult questions on the level of service they wanted and the amount of tax they were willing to pay to fund it.
Dr Keighley made the comments in his final speech as chairman of the British Medical Association in Scotland before stepping down from the role.
Addressing a BMA gathering in Harrogate, he said doctors should be thankful that NHS Scotland had avoided wholesale reorganisation as witnessed south of the Border.
But he added: "What we have in common with the rest of the United Kingdom is a crisis of health provision where the current philosophy seems to be to squeeze more and more from the same resources."
The Herald has been running a campaign, NHS Time for Action, calling for a debate about health funding. Mr Keighley said the independence referendum was a "crucial vote" for Scots but they faced a "far greater decision" over funding the NHS. Looking back on his five years as BMA chairman in Scotland, he told colleagues: "My main regret is that I have not been able to do more than act as a deckchair attendant on the good ship NHS Titanic."
Health Secretary Alex Neil insisted the NHS was one of Scotland's greatest success stories, adding: "Waiting times have improved substantially in recent years." Scottish Labour's health spokesman Neil Findlay added: "It is time for the Health Secretary to listen to what healthcare professionals are repeatedly telling him."