The xiphoid process is the smallest and most inferior segment of the sternum. Its name derives from the Greek word for “sword-shaped,” and it often goes unnoticed until it becomes tender or is specifically sought out. It sits at the lowest point of the central chest, acting as an anchor point for several structures that support the upper body. This extension plays a specific role in the body’s mechanics and serves as an important point of reference in medical contexts.
Finding the Xiphoid Process
Locating the xiphoid process requires gentle palpation along the midline of the body. Begin by tracing the central line of the sternum downward from the neck until the hard bone of the ribcage meets the soft tissue of the abdomen. The xiphoid process is situated at the very bottom tip of the sternum, right where the lower costal cartilages join together.
To find it, place two fingers at the bottom edge of the rib cage and move them toward the center until they meet. This area, where the ribs create an inverted V-shape known as the infrasternal angle, is where the structure lies. It typically feels like a small, firm nodule, a slight indentation, or a pointed projection. In most adults, this structure is only about one to two inches (two to five centimeters) in length.
Structure and Anatomical Connections
The composition of the xiphoid process changes significantly over a person’s lifespan. At birth, the structure is composed entirely of hyaline cartilage, offering flexibility to the infant’s chest. This cartilaginous tissue gradually begins the process of ossification, or turning into bone, as an individual ages.
The ossification process is highly variable, often not completing until a person reaches their 40s or 50s. Once fully ossified, the xiphoid process often fuses with the body of the sternum, creating a single bony unit at the xiphisternal joint. It serves as a central attachment site for several significant muscles involved in movement and respiration.
It provides an origin point for the diaphragm muscle, the primary muscle involved in breathing. It also serves as an insertion point for the rectus abdominis muscle, which helps flex and stabilize the trunk. Additionally, the aponeuroses of the oblique and transverse abdominis muscles connect here, anchoring the muscles of the anterior abdominal wall.
Clinical Importance and Common Issues
The xiphoid process is used by healthcare providers to determine the correct hand placement for chest compressions during Cardiopulmonary Resuscitation (CPR). Applying pressure directly to the xiphoid process during CPR must be avoided. Its fragile nature can lead to a fracture, which carries the risk of damaging underlying organs, such as the liver or diaphragm.
Pain in this region, sometimes referred to as xiphoidalgia or xiphoid syndrome, can result from several factors. Direct trauma to the chest, such as a blow or injury from improperly administered CPR, is a common cause. Discomfort can also stem from inflammation linked to conditions like costochondritis or referred pain from gastrointestinal issues such as acid reflux. Developmental variations, such as a bifid (split) or perforated xiphoid, are common and typically do not cause functional problems.