<s>[INST] For the past two days my heart has hurt really bad. When I lay on my left side it hurts a lot worse then if I am sitting up or standing. When i take a deep breath in, it hurts as i exhale. When I feel my heart with my hand, it feels like its beating very fast, although i never really payed attention to the speed of my heart. I ve also been very tired lately, more tired than I ever have been before. [/INST] Hello, I passed carefully through your question and would explain that your symptoms do not seem to be related to the heart, but to local musculoskeletal inflammation. You should know that the heart lays really deep in the chest, and you can not touch it or even hurt it by deep breathing or laying on the left side.  For this reason, I would recommend performing a chest X-ray study and some blood lab tests (complete blood count, PCR, ESR for inflammation).  Hope I have answered your query. Let me know if I can assist you further.  </s>