Hey Lori, the intercostal nerves come out of the spine in the thoracic region, coming around to the chest, upper abdomen. I don't even recall the name of the e procedure, but I've had a tube put in through my ribcage to drain fluid from around my right lung. Had this done twice actually, and if they bump that nerve, it's excruciating. But, I think what is irritating these nerves is my cough. My wife puts the TENS pads exactly where they need to be, and it helps so much. No pills, no drugs, happy with that.