Yes, after maintaining excellent control of my blood glucose for over a year, I got my first cold after diagnoisis. I was shocked when I test first thing in the morning and found a significantly increased sugar. I stayed in bed, stayed true to my diabetic diet and within two days it came back down to where it normally is. Difficult to know, just keep checking your sugar levels daily, if the raise or lower too much consult your doctor. more than likely. any stress on a diabetic body (flu, cold, fever, pain) can lead to a high blood glucose level. also, are you taking any steroids? prednisone is prescribed a lot for upper and lower respiratory infections to speed the healing process; to decrease inflammation. prednisone will make your blood sugar sky rocket quick. Actually, the stress your body is under fighting off the cold, virus, or infection can cause the glucose levels to rise. This is pretty common, at least for me, anyway. You just have to keep an eye on your blood sugar levels and try to keep it from getting too far out of whack. Your doctor should also be told of this, in case any adjustments in your medications need to be made. Hope this helps! Yes it can. Any stress can affect your blood sugar. Eat carefully and check often. My mother is a diabetic, and it seems like every time she gets ill, her blood sugar level rises higher than normal. Always does for me. It's very unpredictable,it can go up or down. Check your blood sugar every 3 hours while sick and act accordingly. Yes, a diabetic's blood sugar will tend to go up with a cold and ESPECIALLY with the flu. (the flu) is very dangerous to diabetics/others with chronic diseases, thats y u get a flu shot