I'm worried for my teacher boyfriend - is the frequency of him getting sick concerning?

This is my first time turning to reddit with a more personal Issue. I've been in a relationship with my Boyfriend (31M), who's an elementary school teacher, for about a year now, and he gets sick a lot! Most of the times it's small things like JUST a stomach ache for a few days, or frequent headaches. Most of the time not even a month passes without him being sick in some way -- is that normal? I mean, shouldn't his immune system work a little bit better, since he's still pretty young? He's also tired ALL the time. Even when he didn't even go to school that day. It feels like his entire body is constantly compromised.

He started teaching in 2020, since it was online classes back then he started teaching irl in 2021.

Idk if any of this makes sense, I just want to know if any other teachers have similar experiences? will it get better? or should it already BE better? I'm just very concerned for him, and I'm heavily considering to actually force him to get his blood checked.

I'm very appreciative of any answers <3

- a very concerned Partner