stress can cause MASSIVE amounts of changes in one's body - from hair falling out, to T. , to blood pressure problems, to eyesite problems, to tooth problems (grinding your teeth), to muscle and bone pain, to nausea and stomach problems, to lightheadedness or diziness, to urinary and bowel problems, to infections (lowers your immunity),to...well, everything!!
years ago, when my wife and I were going to separate, I lost 27 pounds in a 3 week span...I thought I had cancer!! turned out the stress was causing me to not only lose my appetite but also seriously increase my adrenaline and metabolism, so I was just burning right through anything I put in my body,even though I wasn't exercising as much.