Normal adults generally have 24 ribs, but some may have missing ribs or more ribs due to congenital abnormalities or other reasons, so it is not possible to generalize. In a normal adult, the rib cage is attached to the lateral side of the transverse process of the thoracic vertebrae and extends forward to form the human thorax, which includes the heart, lungs, and other organs. The normal thoracic spine has 12 vertebrae, which correspond to 12 pairs of ribs, from top to bottom, the first to the twelfth rib. The ribs become progressively longer in length, with most of the lower three to four pairs of ribs showing a rib cartilage pattern. The ribs can often present with pathological conditions such as intercostal neuritis, intercostal neuralgia, herpes zoster, rib fractures, and some rib fractures may be combined with complications such as pulmonary contusions and hemopneumothorax. When there is a suspicion of rib damage, a thoracic squeeze test can be performed, and if positive, it indicates a rib lesion that requires further examination and treatment, usually by rib x-ray or CT.