To answer your question, yes, sickness can sure contribute to
blood sugar levels, especially if you are prone to higher levels. I am not a diabetic either, I normally have very good fasting levels and even after I eat, they are good, but, my doctor said that being sick, upset, anxious, can all raise the numbers, the reason, extra cortisol is being released into the blood stream and cortisol raises the blood sugar, fairly fast at times I might add.