Our deepest convictions are shaped by our family stories. When my mother was dying of cancer in the unalloyed luxury of our local hospice, she began to fret about the death from the same condition of her own mother in very different circumstances 60 years earlier. Having run out of money to pay her doctors, this granny I never knew was unceremoniously removed to what everyone called the Poor Hospital, neat shorthand for both the patients and the care meted out to them. In fact, I believe it had once been the local poor house. The memory that so distressed my mum was of two careless porters banging her mother's head and elbows against the walls of a narrow staircase as they carted her from one institution to the other like a sack of vegetables. The image still haunts me.

Our deepest convictions are shaped by our family stories. When my mother was dying of cancer in the unalloyed luxury of our local hospice, she began to fret about the death from the same condition of her own mother in very different circumstances 60 years earlier. Having run out of money to pay her doctors, this granny I never knew was unceremoniously removed to what everyone called the Poor Hospital, neat shorthand for both the patients and the care meted out to them. In fact, I believe it had once been the local poor house. The memory that so distressed my mum was of two careless porters banging her mother's head and elbows against the walls of a narrow staircase as they carted her from one institution to the other like a sack of vegetables. The image still haunts me.

When I was young and fit and carefree, I spent a year in the United States. "What did you miss most?" people asked. At the time, I said it was the BBC. Today, without hesitation, I would say it was the NHS, in the sure knowledge that what happened to my grandmother in the 1940s, is still happening there now.

The National Health Service had a difficult birth in 1948. The new Labour Government of 1945 had promised a revolution in health care but the creation of a system free at the point of use, available to all who needed it, paid for out of general taxation, had proved easier said than done. Consultants, doctors and the Conservatives mounted furious opposition, warning that if the "floodgates" were opened to all, the system would be "swamped". At times in the early years, it certainly came close, as it struggled to satisfy the unmet needs of millions who had previously put up with rotten teeth, strained to read through spectacles bequeathed by dead relatives and died miserably, avoidably and prematurely. The initial budget (£280m a year) was soon surpassed and yet by the time the Tories returned to power, the people loved their NHS so much that nobody dared take it away. Until now.

A striking feature of the coverage this year of the 60th birthday of the NHS was how many commentators predicted that it would not last another 60 years. Karol Sikora, the cancer specialist, foresaw the imminent meltdown of what he described as "the last bastion of communism in Europe". Those on the left lamented the way a unique institution is being slowly strangled by an aggressively free-market economy.

What brought all this to mind yesterday was the arrival in Glasgow of a hero of mine, Julian Tudor Hart, a retired GP. Last night he was due to meet that pillar of the welfare state, Professor David Donnison, in a benign (and far cheaper) collision than the CERN particle accelerator, namely a public conversation at the Western Infirmary.

As a junior reporter on the South Wales Echo in the 1970s, I once interviewed Dr Tudor Hart. He had taken up general practice in the sickly coal mining community of Glyncorrwg in the Afan Valley, where, along with his wife Mary, he instituted the world's first programme of blood pressure control involving the entire community. At a time when GPs largely saw themselves as patching up broken machines, the indefatigable Tudor Harts were offering what amounted to a full service. Mary became a remorseless compiler of data, at one point persuading hundreds of hairy miners to produce stool samples for her collection. What we now call preventive care, they called "anticipatory care", working alongside patients as "co-producers of health", addressing tomorrow's problems as well as treating today's. Many now regard him as the most influential GP in NHS history, providing the blueprint for the switch of focus from hospitals to primary care prescribed by the groundbreaking Kerr Report. But today Tudor Hart is a worried man.

In an article in The Lancet in May he accused the government of turning the NHS "back to the marketplace by stealth and often by lying". The biggest lie, he maintains, is that the PFI/PPP process transfers risk from taxpayers to investors. Instead, he says, £8bn of hospital building will end up costing £53bn and public debate on the issue is stifled by refusing to release contract details on grounds of "commercial sensitivity".

The new Scottish Government would be quick to claim that the NHS is safe with them: that while England is going hell-for-leather for "marketisation and monetisation", that Scotland remains true to the spirit of Nye Bevan. While England embraces polyclinics, Alex Salmond has announced that private contractors are to be outlawed from primary care. Yesterday John Swinney hailed the Scottish Futures Trust as a "much more cost-effective" replacement for PFI.

It would be wrong to make too simplistic a comparison. Many of us remain to be convinced that SFT is more than a rebranding exercise. Meanwhile, Scotland must suffer the consequences of disastrous runaway PFI contracts such as Edinburgh Royal Infirmary. The exclusion of PFI hospitals from last week's announcement about the waiving of car parking charges is a case in point.

Meanwhile, quasi-commercial practices have been distorting the way Scottish healthcare is run for years. An army of NHS press officers are employed to rubbish any implied criticism and turn any statement from staff into bland mince. Under the guise of philanthropy, private sector interests wine and dine GPs and fund post-graduate education. Private operators get jobs within whispering distance of key decision-makers.

Not all recent changes are bad. The new GP contracts incentivise the kind of monitoring that the Tudor Harts of this world have been doing for years. The attempt to bring more healthcare closer to patients is what they want and need.

What he fears though is that as patients become "customers" and staff morph into "factors of production", that notion of "co-producers of health" and the gift relationship that underpins it are being gradually chipped away.

My own view is that doctors and politicians need to be much more up front about the need to prioritise. We need to be told that some drugs and some treatments are simply unaffordable, even within a budget that now hovers around £100bn a year.

Otherwise, there is a danger that the NHS will collapse under the weight of its own hype. Having decided where to draw the line, it's up to us, the patients, to fight to protect "our NHS".

Yes, health inequalities in Scotland are still shockingly wide. It is a scandal that a man in Calton stands to live 28 years less than one in Lenzie. But without the NHS it would be even worse. We need to find ways of getting diagnosis and treatment to those that are hard-to-reach and make the NHS playing field flatter so that the poorest get as much out of it as the stroppy, articulate, internet-savvy middle class. But it's still the best model for a healthcare system on offer.

As Bevan said in the Commons in 1948, "We ought to take pride in the fact that, despite our financial and economic anxieties, we are still able to do the most civilised thing in the world - put the welfare of the sick in front of every other consideration."

Rest in peace, Granny.