<s>[INST] why would the left side of my chest hurt? when the left side hurts I cant breath and I lose my balance and I have almost blacked out at work.  when I bend over or squat at work it really hurts. what could it be? Ive been told that I could have an irregular heart beat and not know it. [/INST] Thanks for your question on Chat Doctor. I can understand your situation and problem. In my opinion, you should immediately consult doctor and get done ECG and 2d echo to rule out cardiac diseases. Your symptoms like left sided chest pain, loosening of balance, black out spells etc. are commonly seen with hypotension and heart diseases. So get done blood pressure monitoring, ECG and 2d echo. You also need Holder monitoring (24 hour continuous monitoring of ECG) because you are having irregular heart beats. So consult doctor and discuss all these. Better to first diagnose yourself and then start appropriate treatment. Hope I have solved your query. Wish you good health. Thanks </s>