I run a managed services department (so essentially I'm an IT director), and I think it's probably one of the most high stress positions that I've ever held. I'm on call 24x7, there is always money on the line, and it's a highly competitive industry.
It was summer, and it started as just a weird burning/itching feeling along my right armpit, and I initially thought that I had gotten some poison oak/ivy/whatever on myself. I rubbed some calomine on it, and called it a day. Fast forward three days, and I had a incredibly painful rash that ran in a band from the center of my chest, under my armpit, and around the back of my shoulder. And holy shit did it hurt. Now I'm only in my early 30's, and for someone my age, Shingles really only has one source - stress. That particular week I had 26 customer facing engagements, and had worked 70+ for over a month.
It was definitely a clarifying moment for me, and was directly responsible for my current attitude where we overstaff our department a little bit to keep the workload manageable, and I keep an eye on peoples timecards, and start hassling them about flextime when they go over 50 hours. The extra work hours just aren't worth the risk of someone having a health meltdown of some sort.