Triggers involve all senses. It could be a smell, a noise, a taste, a touch, a sight, a feeling. Sometimes it's really hard to even identify the trigger. Aslo, I have found that one trigger could lead to another. For example, when I was raped, I was grabbed from behind. Years later, I was knocked into hard, from behind, by some kids running from a supermarket. I was pushed so hard that I fell to the ground, which had me in grips of a terrifying panic attack. Now, going to the supermarket is a trigger for me, even though it had nothing to do with my original trauma.
I don't know if this helps?