<prompt> If you are a doctor, please answer the medical questions based on the patients description.hi im 18 and ive been having a strange feeling in my heart.I didnt tell anyone because i dont want anyone to worry.The feeling is like i have a rock in my heart and my left side always feels funny.Also i have some kind on problems breathing like air is heavy it self.Maybe is axiety or stress right?thank you!  <response>: Hello! Welcome and thank you for asking on Chat Doctor! I understand your concern and would explain that your symptoms dont seem to be cardiac related. Does this feeling change with breathing or body movements? This would be indicative of a muscle skeletal cause. Anxiety could also mimic this clinical scenario. I recommend consulting with your GP for a careful physical exam, a chest X-ray study, a resting ECG and some blood lab tests : -complete blood count possible anemia or infection-PCR, sedimentation rate possible inflammation-kidney and liver function tests -blood electrolytes. If all the above-mentioned tests result normal, the main cause of your troubles would be just pure anxiety. In such case I would advise consulting with a specialist of the field, to help you manage your anxiety. Meanwhile, it is important to avoid caffeine and energy Chat Doctor. Hope to have been helpful! Best wishes! 