The breastbone, also known as sternum, is a flat bone situated just beneath the center of the collarbones . It is divided into three parts: the manubrium, the body and the xiphoid process .
It functions as the connecting point for the ribs with the help of cartilages. Together with the ribs, the breastbone protects the internal organs in the chest, such as the heart and the lungs .
Picture 1: Location and anatomy of the breastbone
Image source: img.tfd.com
Breastbone pain is defined as a painful feeling in the chest area, characterized by pressure and bruising sensations . This may be felt in the bone itself, underneath the bone, or in the side areas of the breastbone. Sometimes, clicking or cracking sounds can be experienced. This is called popping sternum, which is often accompanied by swelling and tenderness .
The pain experienced may be acute or chronic, and may range from mild to severe . Cases with increasing intensity and frequency should be attended by a doctor or a medical professional. However, breastbone pain must not be mistaken for cardiac disorders, as the latter is more serious and needs immediate medical attention.
A heart disorder, such as heart attack, is different from breastbone pain in that the pain in the former is not only felt in the chest area but in the arms, shoulders, and neck as well .
Breastbone Pain Causes
- This condition involves pain in the chest wall caused by inflamed joints between cartilages that connect the ribs to the breastbone.
- Cartilages are essential because it allows the expansion of the rib cage, thereby permitting the lungs to expand freely during breathing. Unlike bones, cartilages are softer and more flexible. These are found in the different joint areas in the body. In the rib cage, the joints that can be found are the costochondral joints (between the ribs and the cartilages), costosternal joints (between the ribs and the breastbone), and the costoclavicular joints (between the collarbones and the breastbone). Inflammation of one or more of these joints causes costochondritis. 
- The cause of costochondritis is unknown, but medical experts say it may be linked to injury to the ribs or breastbone, physical stress from lifting and carrying heavy objects, or from repeated coughing. 
- Similar to costochondritis, the pain in the breastbone experienced in Tietze’s syndrome is also caused by the inflammation of costochondral, costosternal or costoclavicular joints. However, in Tietze’s syndrome, swelling can be experienced. In contrast with costochondritis, only pain and tenderness can be felt in this kind of disease. 
- This is another condition similar to costochondritis and Tietze’s syndrome. On the contrary, the cause of this disease is a viral infection, mainly due to the Coxsackie B virus. Aside from breastbone pain, muscle pain is also experienced in this condition. 
- Heartburn is a burning sensation felt in the chest or breastbone area. A bitter taste in the mouth often accompanies the burning sensation. This is caused by the reflux of gastric contents into the esophagus, which usually happens after heavy meals, or when lying down immediately after eating. 
- The reflux occurs mainly because of the weakening of the cardiac sphincter, the juncture between the stomach and the esophagus. This juncture closes upon the entry of food into the stomach. The stomach contents leak when the cardiac sphincter does not function properly. 
Picture 2: Cardiac sphincter
Image source: biology12-lum.wikispaces.com
This condition may worsen during the following conditions:
- Drinking alcohol or caffeinated beverages
- Eating spicy foods
- Taking some medications such as aspirin and ibuprofen 
Traumas and injuries
- Traumas and injuries in different bones in the chest can cause breastbone pain. One of the areas that can be affected is the sternoclavicular joint. Injury and dislocation of this joint can cause mild to severe pain in the sternum depending on the severity of the injury. 
- Another cause of breastbone pain is collarbone injury. This injury is quite common and may happen at birth due to accidents or falls. Fixing the collarbone alleviates the breastbone pain. 
- Sternum fractures may also cause breastbone pain. This is mainly caused by physical trauma in the chest area. In worse cases, the sternum may break into pieces. However, breastbone pain caused by sternum fractures and injuries are rare. 
- Pain in the muscles attaching to the rib cage is also a common cause of breastbone pain. The muscles usually affected are the intercostal muscles and the pectoral muscles. The pain is mainly caused by heavy or deep breathing, causing strain and pain to the muscles. 
- Surgeries in organs inside the chest cavity, such as open heart surgery (cardiothoracis), may involve the separation of bones in the chest. This causes long term pain, which can be felt even after the surgical wounds are healed. 
- Bronchitis, tracheitis, asthma, tuberculosis and pneumonia are respiratory diseases that may cause breastbone pain due to the difficulty in breathing involved. Sometimes, the pain is not only felt in the breastbone area but on the sides of the chest as well. 
- Anxiety and panic attacks may cause palpitations, psychogenic pain and heartburn, which leads to breastbone pain. 
- Excessive exercise
- Hiatal hernia
- Acute pancreatitis
- Stomach ulcers
- Breast cancer
- Bone cancer 
Breastbone Pain Treatment
Treatment of breastbone pain depends on the cause or origin of pain.
- For costochondritis, the pain and inflammation in the joints can be relieved by taking non-steroidal anti-inflammatory drugs or NSAIDs. This should be taken with food or after meals, as this may cause stomach injuries when taken on an empty stomach. This is also contraindicated in people who are on anticoagulant therapy, and in people with stomach ulcers and reflux disorders. When the patient does not respond to NSAIDs, steroids and anesthetics are usually administered.
- Aside from medications, non-pharmacological treatment can also be done, such as the application of hot and cold compresses, to relieve the pain.
- For fractures, medical attention is necessary. Doctors diagnose the patient for possible injury through X-rays, MRI, or CT-scan. Fractures must be treated immediately to prevent further damage and injuries to the nearby tissues.
- For breastbone pain caused by underlying medical conditions and disorders, it is necessary to treat the causative factor. For digestive reflux disorders, medications for heartburn can be taken. These are available over the counter or with prescription. For respiratory disorders, respiratory drugs are given, depending on the type of the disease. Doctors and health professionals can be consulted regarding these medications.
- Lastly, for anxiety attacks, calming the patient is the first thing to do. The patient’s heart rate must be reverted back to normal. Breathing inside a paper bag may help in alleviating panic and anxiety attacks. [4, 7]