The sternum, or breastbone, is a long, flat bone located in the middle of the chest. The sternum is connected to the first seven ribs by cartilage. This connection between bone and cartilage forms two different joints between the ribs and sternum:
- The sternocostal joint joins the sternum and the cartilage.
- The costochondral joint joins this same cartilage with the ribs.
When you hear your sternum “popping,” you’re hearing the sternocostal and costochondral joints “click” or “pop.”
No one knows exactly what causes these joints to makes these sounds. In many cases, a popping joint isn’t cause for concern unless it’s causing pain, discomfort, or swelling. The popping may occur spontaneously but usually occurs with movement, such as taking a deep breath or stretching.
You might also experience generalized breast bone pain, tenderness, and swelling. It’s possible that the popping of the breastbone can relieve some of the pain you may be experiencing.
There are a number of different conditions that can cause the sternum to pop.
A sternum fracture, or break in the breastbone, is usually caused by direct trauma to the bone. The swelling of the joints associated with sternum fractures can cause popping in this area as well.
Depending on the severity of your fractured sternum, you may need surgery; therefore, it’s important to seek medical attention to inspect your fracture.
Joint or muscle strain
Straining the joints or muscles associated with the sternum can also cause swelling and therefore popping, much like a sternum fracture.
While most doctors simply advise rest, it’s still advisable to seek medical attention if you’re experience pain and popping in the chest area. This allows your doctor to confirm that it is a strain and not something more serious, like a fracture.
Learn more about muscle strain.
Costochondritis is the inflammation of the cartilage that connects the rib to the breastbone. In the case of costochondritis, it can be difficult to differentiate from other types of chest pain, such as a heart attack. For this reason, it’s important you seek immediate medical attention to treat your chest pain.
Learn more about costochondritis.
Stress has been known to aggravate popping sounds in the sternum and to increase swelling and pain in the breastbone area, especially during a panic attack.
You should talk to your doctor if anxiety is making it difficult to do your everyday activities.
A muscle spasm is a sudden and involuntary contraction of a muscle. A muscle spasm can move the joints associated with the sternum out of place, because the tight muscles limit the flexibility of the joints.
This can cause pain as well as popping. Because this pain can be confused with both lung pain and heart pain, it’s important to rule those out by seeking immediate medical attention.
Learn more about muscle spasms.
If you dislocate your sternum, it usually become separated from the clavicle. However, ribs can separate from the sternum as well. In many cases, as the joint that connects the two bones separates, you’ll hear a popping sound.
Though rest is the best treatment, you’ll want to see your doctor to rule out a punctured lung or fractured rib.
Learn more about bone dislocations.
Tietze syndrome is similar to costochondritis, but is almost always seen in the third and fourth rib and most commonly occurs in young girls.
It’s an inflammation of the cartilage that attaches the ribs to the breastbone. There’s usually swelling and tenderness. The pain usually subsides after a number of weeks. However, you’ll need to see your doctor if this pain doesn’t go away.
Though it is possible, arthritis usually doesn’t affect the sternum except at the sternoclavicular joint (where the collarbone joins the sternum) where arthritis sometimes develops. However, if you have widespread arthritis, you may hear a clicking or popping in the sternum as the cartilage is worn down. You’ll most likely want to seek medical attention to deal with the additional complications of arthritis.
If the sternum has been separated during chest surgery, it’s possible to experience post-surgery
Calcification of cartilage
Calcification of the cartilage associated with the sternum is an accumulation of calcium deposits in that area. The calcified calcium can result in small shards that wear away at the joints, breaking down cartilage. This wearing down of the cartilage can cause the popping sound you may be hearing.
In many cases where there is popping of the joint, swelling and inflammation may also be present. Over-the-counter anti-inflammatories, such as ibuprofen (Advil) and naproxen (Aleve) or a painkiller such as acetaminophen (Tylenol), may be used. Popping may go away along with the inflammation over time.
Rest can also help, though this is difficult to achieve with the joints associated with the sternum. Your doctor will usually be able to help you determine the underlying cause of the popping, and treating that will help with your popping symptoms.
In many cases, a popping sternum is no cause for alarm and may even go away on its own with time.
If you’re not experiencing pain but the popping is bothering you, feel free to seek additional treatment from you doctor to determine what’s causing the sound in your chest.