Just wondering if anybody has any idea what could be wrong. I'm a healthy 33 year old male. I have no issues working out and eat healthy. 4 years ago I received 4 concussions in the span of a year. Ever since then I routinely will find myself re-trigger concussion symptoms with any sort of vibrations. Using a power tool can bring it on. I was standing beside a manhole when the lid was dropped on the ground. The vibration from the dropped lid made me feel like I was drunk. Very foggy feeling as well as pressure in the front of the head. Also any light bump to my head will also bring on the foggy feeling as well as a pressure headache. The only relief is lying down and resting. I've been to neurologists and doctors and can't get an explanation. It's happening a couple times a month and may have to look for other employment as I work in law enforcement and don't think another hit would be a good thing at all. Any help would be appreciated. Thanks