I’ve had chronic migraines for decades.
I started to experience migraines initially when I was perhaps 12 or 13 years old.
They progressively, but slowly, worsened — becoming more frequent over the next 30 years.
They were occasionally severe — debilitating, even: vision and intestinal mostly.
In time, I started to become more aware of what, for me, would eventually be a predictable progression of its prodrome. The prodrome could last several days — leading to the eventual “migraine headache”.