<s>[INST] I'm 40 and have had Slight discomfort on left side of my chest, kind of a little pressure, actually felt like i may even stop breathing just for a couple seconds then everything went back to normal but i was so tired and no energy after this episode....What could this have been...actually twice this has happened over last few weeks [/INST] Thanks for your question on Healthcare Magic. I can understand your concern. In my opinion, we should first rule out heart related diseases because left sided chest discomfort is commonly seen with heart diseases. So get done ecg and 2d echo. If both these are normal then no need to worry for heart diseases. Sometimes, stress and anxiety can also cause similar kind of chest pressure and left sided chest pain. So better to consult psychiatrist and get done counselling sessions. Try to identify stressor in your life and start working on it's solution. You may need anxiolytic drugs too. Don't worry, you will be alright. Avoid stress and tension, be relax and calm. Hope I have solved your query. I will be happy to help you further. Wish you good health. Thanks. </s>