The xiphoid process is the smallest and most inferior part of the sternum, commonly known as the breastbone. It starts as cartilage in early life, gradually transforming into bone.
Anatomy and Position
The xiphoid process typically has a pointed, sword-like, or triangular shape, fitting its Greek origin of “xiphos” meaning sword. It is positioned at the inferior end of the sternum, extending downwards from the main body of the breastbone. Its connection to the costal cartilages of the lower ribs integrates it into the ribcage structure.
In infancy, the xiphoid process is entirely cartilaginous, providing flexibility. As a person ages, it gradually ossifies, meaning it turns into bone, a process that typically completes around age 40. Full fusion with the sternal body often occurs in adulthood, but its shape, size, and degree of ossification can differ among individuals.
Biological Function
The xiphoid process serves as an attachment point for several important muscles, contributing to various bodily functions. The diaphragm, a muscle crucial for breathing, attaches to its posterior aspect. This connection assists in respiratory mechanics by providing an anchor for the diaphragm’s movement during inhalation and exhalation.
Abdominal muscles, such as the rectus abdominis, also attach to the xiphoid process. These attachments contribute to core stability and assist in movements involving the torso. While the xiphoid process offers minor protection for underlying organs like the heart, lungs, and esophagus, this role is less significant than the broader sternum.
Common Clinical Considerations
Pain in the xiphoid process, sometimes referred to as xiphodynia or xiphoid syndrome, can arise from several causes. Direct trauma to the chest can damage the structure. Inflammation, like costochondritis, or even excessive coughing, can also lead to discomfort.
The xiphoid process is a landmark in medical procedures, especially during Cardiopulmonary Resuscitation (CPR). Proper hand placement for chest compressions is just above it to avoid injury to the xiphoid or underlying organs. Compressing directly on the xiphoid can cause fracture or internal damage.
Individuals should seek medical attention if they experience persistent pain in the xiphoid area, especially if accompanied by swelling, a visible deformity, or if the pain follows significant trauma. While xiphoid pain is often not serious, other conditions with similar symptoms can be, making a professional medical evaluation advisable.