Triggers as a relevant term extends even further. Actually to anyone who will experience flashbacks or intense reactions as the result of certain stimulus. I’ve said this before, but in drug and alcohol recovery triggers and triggering are very commonly used turns of phrase. This isn’t to correct OP, but to outline to people who use the term mockingly, as though its brand new or undermine people who have poor mental health. This affects more people than just those, and has for a very very long time.

“Trigger” is a medical term for any environmental factor that causes a chronic condition to exhibit acute symptoms. In other words, it’s anything that makes an illness “flare up.”

Migraines have triggers. Acid reflux disease has triggers. Lupus has triggers. Asthma has triggers. Allergies have triggers (though these are usually called allergens instead). Depression has triggers. PTSD has triggers. Addiction has triggers.

Triggers vary greatly from patient to patient; a given condition’s triggers will often follow patterns particular to that condition, but that doesn’t mean a patient will have all of the standard triggers or even any of the standard triggers, and they might have triggers completely unique to them. This is why doctors very often encourage newly diagnosed patients to keep a detailed diary of flareups and anything that might have set them off, in hopes of identifying and avoiding that particular patient’s particular triggers–and that holds true whether they’ve got migraines, allergies, or PTSD. Triggers are triggers.