Yesterday I talked about the ambulance service. It’s a crucial service but it’s one small part of the NHS, the largest public healthcare system in the world, which is made up of a huge number of services and specialisms, each using its expertise to keep people well and relieve suffering. These services don’t operate in isolation – they interconnect to form the web of support that helps people through both critical traumas and long-term conditions.

The scale, complexity and importance of the NHS was shown in the first of a three-part documentary last night on BBC 2. Keeping Britain Alive: the NHS in a Day eloquently showed the beauty of the system, as well as its challenges. The entire series was all filmed in a single day with a hundred camera crews capturing diverse aspects of the service up and down the country. The result is a moving portrait of our healthcare system.

Many people don’t think much about the NHS until they need it for themselves or for someone close to them. There’s an assumption that it’ll always be there for when they do need it, and that it’ll always be free. I’m in no doubt that’s exactly how a healthcare system should be. But we all have a responsibility to think about when and how we use it, and much more importantly to stand up and fight for it when it’s under threat.

And it’s under threat now! Slyly, quietly and persistently the NHS is being dismantled and undermined. We’re being bombarded with scare stories in the media of failures in small specific parts of this huge enterprise. Inevitably there are some failures and weaknesses – many (perhaps most of them) the result of funding cuts and pointless targets.

But be very careful before buying into the idea that the NHS is a failing service that only the private sector can put right. There’s no evidence at all that the nation’s health would be better in the hands of profit-driven private companies.

One story in tonight’s episode followed Lynn, who was undergoing weight-loss surgery. Soon after the surgeon started he was shocked to find a large, potentially cancerous growth in Lynn’s pelvis. He had to stop the operation immediately and later tell her and her family this shocking news. Speaking afterwards he said ‘She’s come in for one problem. We’ve uncovered another problem and then tomorrow, another day in the NHS, we will set about sorting out her other problem. She will get the scans and the tests and the expert opinion. It’s incredible that she’s got this big care blanket around her that’s going to look after her.’

It’s easy to take our healthcare system for granted or be bamboozled by fancy sounding government initiatives. But there’s a great deal at stake and not speaking up for the NHS now may very well mean that when you need a blanket of care wrapped around you, all that’s left is threadbare scraps.

Please don’t join the national moan about the NHS, instead please question its portrayal in the media, sign this petition, get alerts on plans to privatise it, contact your MP, and think about joining campaigning groups taking action to protect it.