You can't explain it to them.
I've now developed personal issues with nurses on this subject.
Nurses are not doctors and they need to come to terms with that fact. Nurses are carers. When it comes to medicine they are not trained in diagnostics, they are trained in how to care for patients and take orders from the medically trained.
A good nurse however should be highly skilled in observation. They should notice issues and problems - which leads me to wonder why there are nearly 150,000 nurses in the UK, many of which give b12 injections, and none of whom seem to have noticed that patients on 3 monthly maintenance jabs have symptoms reocurring long before their jab is due.
So, from where I'm standing they aren't doing that bit of their job right either.
It's rare there is any point in talking to a nurse about b12 deficiency - because they have been trained to give injections every 3 months - and that is exactly what they do because they have been told this is what works.
Shame they aren't noticing en masse that it doesn't - because I happen to think that IS part of their job.
The other bit I have trouble coming to terms with is that in gaining such advances in technical medicine, doctors appear to have decided observational medicine is no longer required in their particular field.
They haven't really any need to actually see patients - just get everyone to queue up for a blood test. If the tests they happen to do don't throw back any positive results then, obviously, the patient is not ill.
No matter what the patient says or their physicial condition.
Their reliance on mechanical medicine is somewhat touching but very stupid. Because they decided decades ago that they no longer needed to listen to patients, then they have made a pig's ear of treating most neurological illnesses for the last...70 years or so.
I've seen it in the CME section of the BMJ article. You get doctors coming on who still don't 'get it.' You get others who are starting to 'get it' but still can't quite believe it. Then you get the few that actually make the brilliant leap that most patients are being undertreated (like the one that I saw that said, "we are undertreating neurological damage."
And you can smell the fear.