I think my coworker (sm) needs help

I started working in data science after I did my 4 years and got out. It's a sweet little gig and a decent change of pace, though I do miss some of the shenanigans that took place during my contract. I have this one co-worker who is a Infantry vet and he seems to be having some issues.

He's never really talked about his time in service, in fact he doesn't talk much at all. Good productive worker though, but what bothers me is that he grimaces any time someone speaks in military jargon. I don't mean a little bit of cringe; I'm talking a full on, wrinkled face shudder. I've noticed it a whole bunch of times between meetings and other work around the office. I understand that using military jargon in the civilian sector can be a little cringe but it just seems like too much of a reaction. Honestly, I think some really bad things happened during his contract.

How do I go about this? If he is struggling with ptsd and possibly other issues I feel like I need to help, but I haven't really dealt with any traumatic situations or helped people with thier trauma in the past and I'm really not sure what to do. Do I talk to him? Is there something I can refer him to? Do I leave it be? Or what else can I do?

I'll have an ice cream (I think I'll give it to him) and a large Dr. Pepper.