What is the sternum?
The sternum is the medical term for the breastbone, a flat, elongated bone in the middle of the chest. Together with the ribs and the spine, it forms the bony frame of the chest and protects important organs such as the heart and lungs.
Structure and position of the breastbone
The breastbone sits just beneath the skin and can be felt easily between the two halves of the chest. It starts at the base of the neck and reaches down to the upper abdomen. Anatomically, the sternum can be divided into three sections: at the top is the manubrium, the broad, handle-shaped plate. Below that is the elongated middle section, known as the corpus sterni. At the lower end sits a small, cartilage-tipped projection called the xiphoid process.
Most of the ribs are connected to the breastbone directly or indirectly through cartilage joints. This connection keeps the chest stable while still allowing it to expand during breathing.
Function of the sternum
The breastbone carries out several important jobs in the body. Together with the ribs, it protects the organs beneath it from injury. These include, most importantly, the heart, the major blood vessels, and the lungs. The sternum also serves as an attachment point for many muscles involved in upper body movement and breathing.
The flexibility of the chest plays a central role during breathing in and out. The sternum moves slightly along with the chest, allowing the whole ribcage to rise and fall.
When does the term sternum appear?
In letters from doctors or medical reports, the sternum is often mentioned when the chest is being examined. For example, an X-ray or CT scan can be used to assess the condition of the breastbone. The sternum also comes up in the context of bone injuries, such as those following an accident or a fall. Sometimes the term is used in connection with heart or lung surgery, as the breastbone may need to be cut through during certain procedures and then closed again afterwards.
Common questions about the sternum
People often feel uncertain when the word sternum appears in a report. In most cases, however, it is simply an anatomical description, not a diagnosis of illness. Only when a "fracture" (that is, a break) or another abnormality of the sternum is mentioned does it refer to a specific finding. In the vast majority of cases, the term simply describes the location or the part of the body being examined.
For those wondering whether the sternum is "important": yes, the breastbone is a central part of the chest. Without it, the internal organs would be far less protected, and the stability of the upper body would be greatly reduced.
Special notes about the sternum
There are rare conditions or changes that can affect the breastbone, such as inflammation, benign growths, or injuries. These are always described using additional terms, such as "sternal fracture" or "sternal infection". The simple word sternum in a report is generally no cause for concern.
In medical texts, the term is used mainly for precise description. A doctor might note, for example, that a particular area of the chest appears unremarkable, or that an examination of the sternum was carried out.
In summary
The sternum is the breastbone, a central bone in the chest that protects organs and provides stability to the upper body. In reports or letters from doctors, the term usually refers only to the anatomical location or the area being examined. Any abnormalities are always named separately, so the word on its own is no reason to worry.
Scientific sources
Groh J, Kern F, Schenderlein A, et al. Traumatic fractures of the sternum – typical distribution and need for subgroups within AO and OTA classification system? Eur J Trauma Emerg Surg. 2025. doi: 10.1007/s00068-025-02910-x
Klei DS, Öner FC, Leenen LPH, van Wessem KJP. Current treatment and outcomes of traumatic sternal fractures: a systematic review. Eur J Trauma Emerg Surg. 2019;45(6):905-915. doi: 10.1007/s00264-018-3945-4
