I don't know/think that the hairballs have anything to do with his numbers, but what I do know is that puking hairballs
isn't normal. People give powdered egg yolk from
here or get egg yolk lecithin in capsules like
these to add to food. Not only is the egg yolk nutritious but the fat in it helps move things along so that the hair comes out in poop rather than puke.

My cats puked up hairballs on commercial wet food and especially when they were eating only dry. Since I put them on a raw food diet, they don't puke up hairballs anymore, which might have something to do with the fat that is in the meat that aids in moving the hair into the poop. Vomiting can be very stressful for a cat.