Our son (age 10) was dx about 2.5 years ago. With him, a growth spurt usually shows up as growth hormones being released between 2-4 am, so his BG will rise (sometimes over 300) between those hours. It rarely lasts more than 5 days, then he goes back into a more normal nighttime pattern. Oncoming illness (or even illness that is not showing symptoms) usually shows up as more consistent highs during the day as well as through the night, and generally only lasts a couple of days (he always gets the "lowest dose" of whatever virus is going through our family). Because these types of spikes often are short-term, I am very cautious about changing his carb:insulin ratios or correction factors; I'll wait for a consistent pattern over 3 days before making an adjustment, making a small adjustment on the 4th day.
I would definitely check with your endo, though, before changing any ratios/factors.