Ever since I was a little kid, everytime I so much as think of, or someone else says the word "citrus", or I read it somewhere - either in English or my native language - I immediately (seems like it takes a fraction of a second) get a physical sensation that is kind of hard to describe; it's sort of like my forehead is freezing cold and in dull pain, but it's also more than that, it's like my literal brain feels cold and like it's shuddering (?). If there follows an immediate stimulation right away (a different thought, contiuing to read, moving on with the conversation etc), it goes away. But, f.e. when writing this post, the feeling persists (it's definitely not as intense as when I had just started typing that post, but it's there all along).

I've read about people who hear colors and taste numbers, so this is what it made me think of, but it's the only word I have this phenomenan with. Nothing else. What could it be, and is there any explanation for it? Thanks.

Edit: don't know if it's related/relevant but I'd wanted to mention I have absolutely no aversion to citrus and love to eat them all. This seems to be an issue with the word/brain association itself. Writing this post has been a nightmare lol I hope I'd get some sort of answer.