There are some things that upset me if I see them. For those I'm following and may follow, here's a list of some of those things. This may not be all of them, and is subject to change as time goes on.

• Animal Abuse, or anything that visually depicts animals being injured or killed
• Anything that degrades autism
• LGBT+phobia
• Insults regarding intelligence, ex. the r-word
• Insensitive jokes/memes regarding things like special needs, gender, race, etc.
• Non-con/sexual harassment and assault (there's a word I could use here as well, but I'd really rather not in case it upsets someone)
• ((sometimes)) Frequent politics in my feed/timeline/etc.
• Gore
• NSFW/R34

Though I usually simply take a break when these sorts of things show up, depending on the circumstances (especially if such content is aimed at me, with the context that they want me to see it), I may unfollow. Please keep these in mind.