Can anyone explain to me why I pee more when I have a cold? [Yes, I currently have a cold, sniff sniff.]

I am not drinking much more liquid than usual [yes, I know you're meant to when you ahve a cold, but I'm busy, OK?] yet I keep having to rush off to the loo every hour.

On a related note, can anyone explain to me why I can usually go out, spend all night in a bar knocking back pint after pint of beer, yet not have to go for a pee?

One possible explanation for my current 'overflow' has occurred to me. Alcohol dehydrates you, right? When I'm ill, I don't drink. Ergo no dehydration, meaning lots of urine produced? Ooh, 'scuse me, need to go...