One I would add to this (though it has never affected me) is diabetes insipidus.
Biggest misconception about this (and doctors don’t help here at all) is it must be another name for type one or type two diabetes because we always hear “there are two types”. Nope, it’s totally sovereign.
Another misconception is it’s one of those rare things. Literally anyone can develop it as a result of a side effect of super common medications such as lithium and a few vaccines that are fortunately no longer in circulation.
And a third is it’s not serious. It’s incredibly serious. Imagine all those misconceptions you hear about diabetes and sugar and apply it to water instead of sugar. Scares me to think about it.