The xiphoid process, also called xiphosternum and metasternum, lies at the level of 10th thoracic vertebrae. It is also the lowest and the smallest part of the sternum, marks the lower limit of the thoracic cavity and the lower border of the heart.
At birth, the xiphoid process is cartilaginous, but it slowly ossifies (turns to bone) from the central core after middle age (usually around 40 years of age). It is connected to the sternum via xiphisternal joint, which lies at the level of the 9th thoracic vertebrae; in older age, due to ossification, sternum and xiphoideus might fuse together 1.
Where Is Xiphoid Process Located?
As we already said, xiphoideus process is the most inferior (medical term meaning situated below, downward 2) region of the sternum. It is an important anatomical landmark of the thorax which some medical professionals use to properly place their hands for CPR.
Anatomy And Attachments
Despite its size, xiphoid process plays an important role in providing anchor points for large muscle groups, ligaments, and rib cartilage:
- At the top the xiphoid process articulates with the lower end of the sternum body, forming a faucet for the cartilage of the 7th rib (see the image above)
- Its anterior surface (anterior – medical term meaning in front3 ) supplies attachments to the anterior costoxiphoid ligaments on either side, and a small part of rectus abdominis (a pair of long muscles stretching across the abdomen, “abs”)
- Its posterior surface (posterior – medical term meaning behind4 ) supplies attachments to the posterior costoxiphoid ligaments, diaphragm, and Transversus thoracic muscle
- Its lateral surface (lateral – medical term meaning a body part that it further from the center of the body5 ) supplies attachments to the aponeuroses of the abdominal muscles (a sheet of tendons that the muscles “use” to attach to each other and to the bones)
- At the bottom, it gives attachment to the linea alba (a fibrous structure that runs down the middle of the abdomen6 )
Though xiphoid process is quite small and may seem insignificant, it is a vital landmark for:
- CPR – you can use xiphoid process to determine where exactly you should put your hands during cardiopulmonary reanimation
- Distal margin of the heart
- Superior end of the liver
- Central tendon of the diaphragm
- Distal, anterior end of the thorax
- Subcostal angle – angle between the lower borders of the costal (rib) cartilages (you can palpate it yourself)
Causes Of Xiphoid Process Pain
Most common causes of pain in and around the xiphoid process are physical injury, GERD disease, and xiphoid syndrome.
Physical Injury – Swollen, Sore Or Broken Xiphoid Process
Even though the bone is quite small, in case of a fracture it can get detached from the sternum and pushed down towards to the diaphragm and even the heart; for this reason patients with any sort of chest injury (from collision or impact to the thorax) need to be checked out by medical professionals.
Injuries and fractures can also commonly occur when inexperienced individuals attempt to administer CPR. Two of the most common mistakes are:
- Applying too much pressure – thorax is quite strong, it is designed to protect some of the most important structures and internal organs, but it has its limits. Applying too much pressure can easily cause dislocation or even bone fracture.
- Wrong hand placement – if you place your hands too low on the sternum, you might fracture xiphoid process, even if the pressure is optimal. You need to move your hands towards the center of the sternum, between the nipples.
There was also an interesting case of a 66-year-old man who was presented with an abdominal pain, tenderness and pain in the middle of his chest7. The X-ray revealed an abnormal elongation of the xiphoid process. It was later determined that the xiphoid process was broken, pulled down by the abdominal muscles, elongated and later reconnected with the sternum.
The patient then underwent surgery and the process was shortened.
Xiphoidalgia – Xiphoid syndrome – Xiphoid Process Pain When Pressed
Xiphoidynia, also known as the xiphoid syndrome, is a condition where the patient feels pain and tenderness in the lower portion of the sternum. There are some opposing opinions on the frequency of this condition since some researchers think it is rare while others object by saying it is often overlooked.
One of the reason it is commonly overlooked is presence of another, more severe medical condition8, such as:
- Heart disease
- Gallbladder disease
- Bone disease
The main characteristics of the xiphoid syndrome are intense, sharp xiphoid process pain when pressed, intensifying pain when bending over or twisting and tenderness to touch. In more severe cases, the pain can radiate to back, neck and shoulders and become so intense patients will feel nauseated9.
GERD – Gastroesophageal reflux disease
GERD usually occurs when stomach acid starts flowing back up the food pipe (esophagus) because a band of muscles at the end of the esophagus does not close properly. This irritates the lining of the esophagus and causes GERD10.
So what does stomach acid have to do with xiphoid process pain? Well, the location plays a vital role here. The esophagus is located behind the windpipe (trachea) which runs just behind the sternum. So the very proximity of these structures is responsible for pain manifestation in this region.
Xiphoid Process Protruding (Sticking Out) After Losing Weight – Tender On Touch
Protruding xiphoid process is generally not that common (in adults), but people who lose a substantial amount of weight tend to complain about this problem. In some cases, patients feel no pain whatsoever, while, in others, the area feels tender, painful and sometimes swollen.
So what is the cause of this protrusion in overweight people? If you read the entire article, you probably noticed the case of a 66-year-old patient with abnormal elongation of the xiphoid process. And, as you could see, it was determined that the Process was broken, pulled down by the abdominal muscles, then elongated and reconnected with the sternum.
A common cause of this fracture is trauma, but it can also be caused by a vigorous physical activity where the rectus abdominis pulls on the xiphoid process and causes fractures and/or dislocation.
A more likely cause of this protrusion, however, is visceral fat (fat found within the body). In obese people, this fat can put additional pressure to the internal organs and the rib cage itself, causing it to expand; and, since xiphoid process is cartilaginous, it can easily get pushed out of its place and stick out. And as the person loses more and more weight, the XP becomes more noticeable.
Most doctors agree that this is not the cause for any concern, on the contrary – its completely normal; but if you experience any sort of pain or tender xiphoid process on touch, you should talk to your GP for just in case.
Xiphoid Process Pain Treatment
Of course, there is no one correct solution for xiphoid process pain. The treatment will largely depend on the cause of the pain and the condition which lead to the pain.
Doctor will usually start by giving the patient some analgesics, to relieve pain. In more severe cases, where the analgesics don’t work, steroid injections might be employed as well.
Applying heat and ice will also help relieve pain and swelling; changes in diet and light exercise will help with GERD and if there is any sort of anatomical abnormality (like in the case of our 66 year old) surgery might be required.
- (1912.) Gray H. Anatomy of the human body
- The Free Medical Dictionary. Retrieved from http://medical-dictionary.thefreedictionary.com/inferior
- Image credits :”Gray116” by User Magnus Manske on en.wikipedia
- The Free Medical Dictionary. Retrieved from http://medical-dictionary.thefreedictionary.com/anterior
- The Free Medical Dictionary. Retrieved from http://medical-dictionary.thefreedictionary.com/posterior
- (August 28. 2013.) Definition of Lateral, Medicine.net. Retrieved from http://www.medicinenet.com/script/main/art.asp?articlekey=6226
- (May 2014.) Linea Alba, Wikipedia. Retrieved from http://en.wikipedia.org/wiki/Linea_alba_%28abdomen%29
- (2011.) Postoperative elongation of the xiphoid process, National Center for Biotechnology Information. Retrieved from http://www.ncbi.nlm.nih.gov/pubmed/21697798
- Xiphoid Syndrome Symptoms, Diagnosis, Treatment and Causes, Right Diagnosis. Retrieved from http://www.rightdiagnosis.com/x/xiphoid_syndrome/intro.htm
- (July 2009.) Xiphoid Process, Wikipedia. Retrieved from http://en.wikipedia.org/wiki/Xiphoid_process
- (July 31.2014.) GERD – Definition, Mayo Clinic. Retrieved from http://www.mayoclinic.org/diseases-conditions/gerd/basics/definition/con-20025201