What do we know about them in the wizarding world, in particular illnesses that come on suddenly and result in death? And if we don't know much, then what do you think these illnesses would be e.g. are they similiar to any of our own?
We don't know much about magical illnesses, but we do know that wizards and witches aren't immune from even the most mundane Muggle illnesses, like the common cold. I think wizards and witches are just as likely to get fevers, cancer, swine flu, AIDS, etcetera as any Muggle.Originally Posted by xOxLyDzxOx
However, we do know of some magical illnesses, like Dragon Pox and Spattergroit, so I think these maladies are magical rather than purely biological in nature, and are attracted to magic, and therefore don't inflict Muggles.
But then again, these "wizarding illnesses" could just as easily be Muggle diseases, but just with different names. Since wizards and witches generally live longer than Muggles, it is possible that they could have discovered things like Alzheimer's and other old-age related diseases before Muggles did, and would have their own terms for them.
Presumably, magical people are just as likely to catch diseases, but they would probably be more adept at curing them.
Tim the Enchanter
This is a very interesting topic because it brings up the questions of how wizards deal with "Muggle" illnesses like AIDS or cancer. Are they incurable in the wizarding world, as well? I would tend to think so, because of the main observation that if they were curable in the wizarding world, then surely Muggle-born Healers would realize the significance of such a cure and try to construct one in the Muggle world, as well. (Then again, maybe they wouldn't - Counting to Five Thousand by Rhetor is an excellent fic that explores this concept).
There are, of course, magical diseases that magic cannot cure, and I think we've seen some of them in the books.
EDIT: I agree with Tim that Muggle diseases are probably known by different names in the wizarding world (St. Mungo's has floors for creature-induced injuries, magical bugs and diseases, plant poisoning, and spell damage, but none for diseases that aren't caused by magic).