If someone triggers you figure out what is that unhealed part of you that needs release. I get triggered by folks who are constantly judging and criticizing others. I had a mom who did it all day, every day. So when I am among others who are in full nasty judgment mode I shut down. I get angry. And guess what? I start to judge them. So what triggers me is the unhealed parts and I do it myself towards them.
Your job is to decipher what and who you keep in your life that make you feel good. Let go of those things and people who make you feel otherwise.