cold has affectd my BGs more than ever before

Of course I've had a cold before, but usually my BG hasn't been much affected, just a SLIGHT increase. However , this morning, I'd hit 7.2. I normally don't go anywhere near there, more like 5 fasting. Is there a particularly vicious cold virus about? I've been as careful as usual with eating, but being congested snd finding it hard to breathe, [even whilst taking Sudafed. I know it says not for diabetics, but until I get a good explanation of why, I'll keep using it!] I've eaten LESS than usual!
There's nothing listed on the Sudafed leaftlet which might make BG go up. Anyway I've ue it before without problems.
Any suggestions folks?
Hana

Thanks Ivinghoe,
It's nice to know I'm not alone.
I'm VLC diet and exercise plus minimal Metformin, so my scope for adjustment of medication is slight. I can increase the Metformin. Since I'm on 1 g per day and the maximum dose is about 3 x that, I'm pretty safe.
Hana
PS 6.8 this morning and feelin pretty wiped out. Very unusual for me!