Triggers for me are dehydration, tiredness, stress and oo much bad food. I found that eating meat and dairy also had a massive effect on me and led to me giving them up. I have been more or less Vegan since figuring that out 20 odd years ago.
I should have added that I have also found exercise really helps me as well. High cardio if I feel I could be getting an attack coming usually see's it off.
https://migraine.com/blog/msg-untangling-this-hidden-migrain...