What happens when you have a migraine?

Question

My mum has migraines alot, but all she will tell me is "it's like a headache, but not".

What is a migraine? And what happens to you when you have one?

Answer 1

A migraine is caused by the constriction of capillaries in the brain and matter surrounding the brain.  The constriction of blood vessels causes a lack of blood (and thus oxygen) to the brain.  This lack of blood causes visual hallucinations, typically in the form of bright, flashing bands that slowly progress from the middle of the visual field to the edges of the visual field.  It also typically results in nausea.  Many people also a non-specific cognitive decrease (that is, they feel dopey and slow; bad at problem solving, etc.).

After half an hour or so, the blood vessels begin to allow some more blood flow into the affected areas.  This is what causes the pain.  It is  exactly the same type of pain as a "brain freeze" from eating ice cream too quickly, and it has the same cause: blood rushing back into an area that was lacking blood flow.

So in short, a migraine is your brain freaking out due to lack of blood, causing nausea, hallucinations and cognitive deficits, followed by a headache similar to a "brain freeze" for multiple hours.  Not fun :(

Answer 2

I have had a few and they are definitely not fun, somewhat akin to having a seizure but you remain concious. I have a fact sheet linked below.