I won't get too much into the details but my youngest (3) has had some goofy health issues. Nothing terribly serious, but certainly concerning (slow healing, infections, asthma, somewhat serious hearing issues, adenoids removed, etc..). We have no real answer as to why yet and the doc agrees it's not "normal". He's an active and normal kid outside of this stuff and it doesn't affect his daily life other than coughing spells.
Anyway, I am wondering if we should invest in some type of "full panel" blood test type of thing to (potentially)rule out any serious diseases or conditions. My wife called the doc about it and got the assistant who said she would ask the doc. The doc then responded through the assistant with "what tests would you like to run"?
I have no idea other than "The important/big ones"

and he's obviously kind of blowing me off, trying to point out my lack of knowledge in a subtle way(which I may deserve). I admit an ignorance on the issue and am really just spit-balling out of fear/hope for preemption.
So anyway, are there any tests that make sense to run if I'm willing to pay? Or maybe I'm just being paranoid? He''s had blood tests but as I understand it the scope of them was pretty narrow and in response to the days specific issues..
Thanks guys.