As the thread has moved on so quickly I haven't read all of the catchup on this thread, but there is two separate things,
Last year I had a series of migraine and headaches, it was investigated including a Cat Scan but they didn't find anything, ( yes wait for the joke-Nothing, not a brain

.
That wasn't really concluded.
However I do have a blood condition that requires steroids to keep in under control, its a rare condition and baffles most consultants, I have had it diagnosed for about 10 years but when I was diagnosed I was one of the few if any in the UK that had been diagnosed, now there are more people who doctors know have this condition, It is also know in the USA.
It doesn't effect anyone else just myself, but if untreated could have serious issues for myself and my organs.
They do not know if the headaches are linked or result of steriods, or stress from work. But on Monday I had to travel around London a lot, for business and on the way home in busy rush hour my tube had to stop as the tube in front stopped as someone pulled the emergency lever and we were stuck in a tunnel for quite some time, in a hot tube that didnt help.