About a year and a half ago I suddenly developed severe chest and back pain and felt like I couldn't breathe. I was convinced I was having a heart attack. I went to urgent care (twice, in fact) but blood tests, x-rays and EKG showed nothing wrong with my heart, lungs or ribs. I was told it was probably just tension myalgia due to stress. Since then it's come and gone, sometimes becoming so severe that I've had to stay home from work and barely move. I'm also a marathon runner and sometimes get the feeling that my chest is being compressed and I can't breathe while I'm running.
Just this November I discovered I'm B12 deficient with macrocytic anemia. Since starting self-injections 2.5 months ago, the chest/breathing issues have become noticeably better. I'm so relieved! My question is, is this a symptom of B12 deficiency? I understand the "sighs" and shortness of breathe can occur with B12 deficiency but my symptoms seemed so extreme I assumed they must be from something else.