Small plane with unpressurized cabin?

I have to fly from Chicago to Houston next month for a medical appt. I had 3 lymph nodes removed, which maybe doesn't put me.a4 very high risk but I'm tryintg to play.it safe. I'm broke AF so I was looking into travel assistance programs. Several of them ask if you can travel in a small plane with a pressurized cabin, and I don't know how to answer. I know commercial flights with pressurized cabins can be problematic, but I guess I'm wondering if unpressurized cabins are somehow worse? Is it worse for blood clots too?