Teenage anger and agression

I have a 18 year old son away at school who is a good young man. He tells us pretty much everything. He called and asked me to get him a Dr. appointment because he thinks something is wrong with him. Things that use to roll off his back makes him snap and the anger makes him out of control.  He will break out in hives even when he is not upset. I know he is under the same pressure as any college student but this is totally freaking him out. He has a pretty tough case of acne but not on meds for it. He is very outgoing and in ROTC and loves it and the people he lives with. I feel pretty confident that he is telling me everything as he is the one that wants answers. I had Graves Disease at 25 and I remember feeling like I was going to loose my mind at times but everything I read says it is a mostly female disorder. Could this be happening to him also? What about testosterone levels? Anyone with any suggestions your help is greatly appreciated. Id love to go armed to the doctor with the right questions!!