SIMPLE GUIDE:
Body Horror: Things that cannot happen in real life. EX: The Thing, stomach mouths, eyes on hands, etc
Gore: Fresh injuries, often severe. EX: Severed leg, gutspill, deep gashes, etc
NEITHER: Healed injuries and burns, congenital differences, missing appendages, etc. If I could theoretically go to the store and see that character browsing the isles- It isn't body horror or gore. That's just a person. *AND the amount of people that tag, not just fictional characters, but real human beings as body horror is staggering. Its not solely a fandom issue, ableism and bigotry against anyone that looks sufficiently "different" is prevalent in real life and has devastating consequences.
(Modified) from my comment left on this post.
My "yes, and" to this is that I think that there is space in the body horror genre for writing about a thing your own body is doing, in some cases.
A big part of body horror is obviously about the unnatural, but there is also a large part of it that is about violation and/or loss of control of your body (whether by someone else or through some other force).
For example, I've written body horror about the tumors my body keeps growing, because there are ways in which that feels like a violation of my body, even if it is coming from my own body. Forced or unwilling pregnancy is another thing I have thought of writing in that way, and that I think there absolutely should be space for in the genre.
These are things that happen in real life, but I don't think that should exclude them from the genre of body horror.
