GPs are not trained in understanding Thyroid conditions and I am afraid they seem to have little knowledge of Type 1 diabetes either (well in my experience). They certainly know very little about the interaction between the two.
I agree very little is understood about the thyroid and how thyroid diseases whether hyper or hypo affect the people who have these conditions. My GP was prepared to see me become completely immobile rather than prescribe another form of treatment. So I changed my treatment anyway.
A friend of mine has been suffering from Irritable bowel disease, depression, anxiety, chronic fatigue syndrome (CFS), arthritis, headaches, sore joints and muscles, pain on walking etc etc. GP kept saying there was nothing to show what might be wrong and eventually lumped all symptoms under CFS. It was only on visiting a private consultant that it was found that my friend was severely hypothyroid. Want to guess my friend's gender? Oh and hypothyroidism was prevalent in the family.
No prizes for guessing correctly.
As for Casualty being fiction - well - that would be fine but some people do take it literally.