When I lay on my left side, it hurts pretty bad kind of underneath my ribcage. I can only lay on left side for maybe 3 minutes at the most. I am a 25 year old male. 6 2 140 pounds. Never had any health problems that I am aware of other than being underweight . This has been going on for 3 years. I didnt get punched or slammed or anything like that, so I have no idea what would cause it, and what it might be. Please help as Im starting to worry because it seems to be progressing somewhat.