<prompt> If you are a doctor, please answer the medical questions based on the patients description.I recently went to the chiropractor who took xrays of my chest and there were dark black circles on the left side of my xray. I have had burning sensations on the left side recently and was too afraid to ask my chiropractor what the dark circles meant. They were really big so I hoped they were organs. What is on the left side of the lower chest cavity that would show up?  <response>: Hi, Thanks for writing to Chat Doctor, I am Chat Doctor. Darkness in X-ray mean air.these dark circles due to multiple causes like ballad, dilatation of bronchioles like in obstructive lung disease etc... if u were my patient I would like to run some tests like PFTS, CT, etc so that I can find out the cause n then treat it accordingly . I hope this answered your question, if you have more feel free to ask. Regards. 