I have had these all my life, they can be so unpredictable, I can go months without one and then get 2 in a day.
Recently had a bout of them, so popped to GP who has prescribed propranolol 80mg slow release. He says that stress plays a huge part..of which I have in abundance at the moment with elderly parents., but can be weather changes, bright sunlight, caffeine.
They were definitely more frequent during perimenopause
They are scary, but I now just accept that it's part of a migraine, and feel lucky the awful headache doesn't follow.