Pain

Taken from Wikipedia:

Migraine (from the Greek words hemi, meaning half, and kranion, meaning skull) is a debilitating condition characterized by moderate to severe headaches, and nausea.

I have for years suffered from migraines for years, some lesser more like bad headaches - but the one today was crippling (still is as I sit here typing wearing my sunglasses with the curtains tightly closed). At least, for the first time, I have made a mental note of all the symptoms leading up to the blinding pain.

a) Excessive tiredness
b) An aura effect (blurring around the vision)
c) Extreme nausea
d) Followed by the blinding headache along one side of my head

As a further note I'm timing the length so that when it happens again I can adjust my life around it. Well that is my hope anyway...