The intercostal nerve is under the rib cage in the chest, emanating from the intervertebral foramen of the thoracic spine, and travels along the nerve groove behind the lower edge of the rib cage, running diagonally from the back to the sides all the way down to the front. Its role is mainly to innervate the intercostal muscles so that they can move, which is an aid to breathing. There is also innervation of the local muscles and skin. If there is an inflammatory stimulus, such as intercostal neuritis, it can cause pain or numbness in the area innervated by the intercostal nerve, but the pain is predominant. In this case, it may be possible to relieve the pain with nerve-nourishing drugs or with a bit of closure. But overall, it is recommended to go to the hospital and let the doctor examine it before making a more correct treatment.