So I started working at a casino nearly three weeks ago. I work from 11pm-7am and it's obviously been draining me. I'm used to days, not nights. In the past two weeks, I've noticed between the hours of 2-4 a.m I get really bad acid reflux, upper back pains (all across the shoulders) and random headaches. I am used to standing on my feet for 8 hours, so I don't know what the difference is. I've always had problems with acid reflux, but only normally when I eat spicy foods. I eat before work and don't eat at work, unless it's a small salad & the only beverages I drink is pineapple juice or water. The back pain is what gets me the worst. It feels like everything gets tight and I can't relieve the pain. I've taken ibuprofen and tried stretching. I know this is a long shot, but does anyone else have any better suggestions?