I am a 28 year old female who has hypothyroidism. I am currently on 125 mcg of levothyroxin a day. Three days ago I had a little dizzy spell while driving. I had to pull over and I let my husband drive the rest of the way home. Since that, I have felt my heart palpitating like crazy. I chalked it all up to psyching myself out from that dizzy spell. I finally went to the ER just to reassure myself I wasn't having a heart attack or anything. It all is just crazy to me. I feel like I can't concentrate while driving. It's as if I can't focus on one thing at a time. I went to dinner with my family the other night and I had to walk away because I was feeling like everyone was just talking around me and I wasn't present. I am normally a very social person, with minor anxiety about petty things. But, this feeling of having a lack of mental focus and feeling like my heart is going to jump out of chest is almost debilitating. I am having a follow up with my primary doctor tomorrow to check on my levels, but didn't know if any else had ever felt this way? It is truly scary.