The xiphoid process is the small, triangular piece of bone at the very bottom of your sternum (breastbone). It sits right where your lower ribs meet in the center of your chest, in the soft spot just above your stomach. Of the three parts that make up the sternum, the xiphoid process is the smallest and lowest, with its tip pointing downward at roughly the level of the tenth thoracic vertebra.
Where Exactly It Sits
Your sternum has three sections stacked vertically: the manubrium at the top (near your collarbone), the body in the middle (the longest section), and the xiphoid process at the bottom. The xiphoid connects to the sternal body at a joint called the xiphisternal joint. On either side of that joint, the cartilage of your seventh ribs attaches via small ligaments, anchoring the lowest true ribs to the base of the breastbone.
If you press your fingers into the center of your chest and slide them downward past your ribs, the firm nub you feel at the bottom of the sternum is the xiphoid process. It sits in what anatomists call the epigastric region, the area between your ribcage and navel.
It Starts as Cartilage and Slowly Turns to Bone
Unlike most of the skeleton, the xiphoid process remains soft cartilage well into adulthood. It typically begins to harden (ossify) sometime in your 30s. The joint between the xiphoid and the sternal body usually completes fusion by the fourth or fifth decade of life, with some variation between men and women. Forensic specialists actually use this timeline to estimate age: a fully fused xiphisternal joint suggests the person is at least 37 years old, while an unfused joint suggests they’re 45 or younger.
What It Does in the Body
The xiphoid process serves as an anchor point for several important structures. The diaphragm, the dome-shaped muscle responsible for breathing, attaches in part to the xiphoid. So do portions of the abdominal wall muscles that run vertically along the front of your torso. The ligaments connecting your lowest true ribs also attach here. While the xiphoid itself is small, its role as a meeting point for these muscles and connective tissues makes it structurally important for both breathing and core stability.
In medicine, the xiphoid process is a key surface landmark. It’s the reference point for CPR hand placement and for certain emergency procedures. Pericardiocentesis, a procedure to drain excess fluid from around the heart, typically involves inserting a needle just below the xiphoid and directing it toward the left shoulder. Surgeons and emergency physicians rely on this bony landmark precisely because it’s easy to locate by touch.
Why It Varies So Much Between People
The xiphoid process is one of the most variable bones in the human body. In a large imaging study, about 63% of people had a single-tipped (monofid) xiphoid, roughly 33% had a split or forked (bifid) tip, and about 5% had a three-pronged (trifid) shape. Around 3% of xiphoid processes curve at the end like a hook, bending either forward or backward.
Natural holes in the xiphoid, called foramina, are also remarkably common. One study found them in 43% of patients, another in 27%. These holes are completely normal and usually cause no symptoms, but they can be mistaken for fractures or abnormalities on imaging if a radiologist isn’t expecting them. Incomplete fusion between the xiphoid and the sternal body can create a gap called a pseudoforamen, reported in roughly 1% to 4% of people.
The Lump You Can Sometimes Feel
Because the xiphoid process sits just beneath the skin at the base of the sternum, many people notice it for the first time and worry it’s an abnormal growth. This is especially common after weight loss, when less tissue covers the area, or in people whose xiphoid angles forward. A protruding xiphoid is almost always normal anatomy, not a sign of disease. That said, if the area is hard, tender, or new, other causes should be ruled out before attributing the lump to the xiphoid alone.
A particularly large or elongated xiphoid process can itself cause problems. Case reports describe xiphodynia triggered by an unusually large xiphoid pressing on surrounding soft tissue, and in rare instances, the xiphoid can elongate after chest surgery or even after CPR compressions.
Xiphodynia: When the Xiphoid Hurts
Pain originating from the xiphoid process is called xiphodynia or xiphoid syndrome. It typically presents as tenderness right at the base of the sternum, but the discomfort can radiate surprisingly far: into the chest wall, upper abdomen, throat, back, neck, shoulders, and arms. Because the pain mimics so many other conditions, people with xiphodynia often undergo extensive testing for heart disease, gallbladder problems, or acid reflux before the xiphoid is identified as the source.
The most common symptoms overlap with cardiac and digestive complaints: chest pain, upper abdominal pain, nausea, vomiting, and diarrhea. Pain tends to worsen with bending forward, twisting the torso, or eating large meals. Trauma to the chest or upper abdomen, including rapid acceleration-deceleration injuries like those from car accidents, can damage or partially dislocate the xiphisternal joint. Arthritis and, rarely, malignancy can also affect the xiphoid.
Several underlying conditions are associated with secondary xiphodynia, meaning the xiphoid pain accompanies another problem. These include gastroesophageal reflux disease (GERD), gallbladder disease, and coronary artery disease. In these cases, treating the underlying condition often improves the xiphoid pain as well.
How Xiphoid Problems Are Diagnosed
CT imaging is the primary tool for evaluating the xiphoid process when something seems off. Thin-slice CT scans (1.25mm or less) with reconstructed side-view images give the clearest picture of the xiphoid’s shape, size, and relationship to surrounding tissue. Researchers have looked at whether the angle between the xiphoid and the sternal body can predict xiphodynia, but recent evidence suggests that angle alone isn’t a reliable diagnostic sign. More useful is checking whether the xiphoid is compressing nearby soft tissue.
Ultrasound is also being explored as a diagnostic option. Because it can be performed in different body positions, it may be especially helpful for evaluating whether soft tissue compression changes when a patient bends or moves, which is often when xiphodynia symptoms are worst.