Probably push it up, illness and stress generally can cause higher sugar levels, and some antibiotics can push them up a bit more. Also depending on what infection you have they sometimes use steroids those are also known to increase blood sugar levels. Plus, hospital food is very carby, not great for diabetes. But the only way you know what the combination of everything going on does to your individual sugars is to test, test, test.
Likewise @ally1 it’s a predictor of infections for me. I have 1 day of higher sugars without any reason I shake it off, day two I book a drs appointment for 3-4 days time just in case. Then on day 3 if I start showing UTI symptoms, drop my water sample at the drs, and then go to my appointment to see if dr wants to try tablets or if I’m going to the hospital for IV antibiotics. If it’s not a dr I see regularly it confuses them that I booked the appointment before becoming symptomatic of UTI.
I know my body and conditions.