Hi
@hughinoo, From my experience as a type 1 diabetic, not as professional opinion or advice.
By 'flu do you mean runny nose, blocked sinuses, cough or are you referring to the 'real 'flu with high fevers, cough, sweats and sometimes tummy upset?
If it is the former, I have noticed that sometimes these symptoms can be very similar to allergy symptoms and, since the top two allergy seasons are autumn (fall) and spring, you that could be the answer, whichever hemisphere you live in.
If I contract a cold, upper respiratory tract infection or URTI as the docs call it, my BSLs and hence insulin requirements tend to go up whereas with hay fever they do not unless I am stressed by lack of sleep due to the allergy.
If is it the latter, then my BSLS will most definitely go up. Even with the annual 'flu vaccination my BSL go up and I require >30% increase in my insulin for 4 to 5 days. Public health authorities say the real 'flu usually lasts 10 days or less, unless complications like pneumonia occur. If I had had a bad cold or flu and high temperatures settled and came back with a vengeance I would be off to the doctors pronto.
If I was suffering intermittent sweats and measurable temperatures > 38 to 39 degrees C I would be off to the doctors also, particularly (as mentioned in public health information) I had been travelling overseas in the past 12 months or so.