I have the sort of headache that usually means I am dehydrated ....

[TooTicky]

...but I'm not. I am drinking lots but still feel the same. Why?

Tired? Going down with a cold?

tired

Hm, tired maybe. It doesn't normally affect me this way though.

if you've had several nights of short/broken sleep then you could find that's the reason - I hardly sleep as it is, but if for some reason (ie I get carried away with stuff on the computer) I get even less sleep for a few days then a few days later I get the headache.

Ah. Maybe I have been staying up late MNing a little more than usual.

get yourself off to bed early then (says she who's tired but will no doubt not go to bed until 12.30 at the earliest )

I'm off! (nearly...)

Headaches can be a sign of high blood pressure. Get it checked next time you go to the doctor just in case.

Really? My blood pressure is normally v. low.

Sinus headache?

Ah, could be... thanks.