Cause of pain:
Benign chest wall pain is most likely a transient and fleeting irritation of the pleura, the slippery membrane that lines and protects the lungs. The pleura are very sensitive to pain, and for reasons that are usually not clear, some momentary irritation causes a painful sensation that can be quite severe, but that quickly subsides. This condition has no medical significance whatsoever. It is very common. Most people will experience these symptoms at some point in their lives.
Characteristics of pain:
The pain is usually a sharp "catch" that interrupts a breath, and that returns with each breath for a few moments - then it subsides. It is not related to exercise, and generally can be localized to a specific small area (smaller than the palm of the hand) on the chest wall. It usually lasts for less than a minute, but can come back on and off for an hour or so. Frequently patients will describe recurrent symptoms every few weeks or months.
Evaluation:
This condition can be evaluated by taking a careful history. The condition is very common, and very easy to diagnose by history - as long as the doctor is aware of it and understands it. The important thing to keep in mind is that this condition is completely benign, and is not related to any medial problem or any abnormality.