The left side of my chest area "feels" like it is bruised internally, but I have not injured it; feels like a muscle ache. I can breath normal and fill my lungs without it hurting, but it hurts when you try cough, lay down on that side, bend over to do anything, or stand up from sitting. I have been coughing hard at times due to allergy issues for the last few weeks. It has been better and worst depending on the day for the last 4 weeks, but it is not going away. Not sure what is going on.