I've spent my whole life going to allergists and getting prescriptions for allergy shit that didn't help. All of my tests would come back negative except for a mild allergy to cats, which I'm never around and am rarely around people that own cats who would have dander on their clothes.
Now I'm doing treatments for migraines and my allergies are dwindling. Before I thought I had a migraine because my allergies were really bad and my sinuses were so congested, but it's the opposite - I have allergy-type symptoms because my migraine is so bad it triggered everything in my head to explode basically.
Made a lot more sense when the doc said it, but basically a migraine can trigger much more than just pain. Nerve endings are going wild all over my head! But omg my allergies and migraines are so much better.