Medically reviewed by Kashif J. Piracha, MD The diaphragm is a dome-shaped muscle that separates the chest from the abdomen. This muscle, also called the thoracic diaphragm, is the main muscle used ...

It's one of the main muscles involved in breathing. Most scientists believe the pain is caused by a reduction in blood supply to the diaphragm, causing it to cramp. The stitch is caused by fluids ...