[2] Sternal fracture can interfere with breathing by making it more painful; however, its primary significance is that it can indicate the presence of serious associated internal injuries, especially to the heart and lungs.

[3] Signs and symptoms include crepitus (a crunching sound made when broken bone ends rub together),[1] pain, tenderness, bruising, and swelling over the fracture site.

[4] The fracture may visibly move when the person breathes, and it may be bent or deformed,[4] potentially forming a "step" at the junction of the broken bone ends that is detectable by palpation.

[citation needed] Vehicle collisions are the usual cause of sternal fracture;[3] the injury is estimated to occur in about 3% of auto accidents.

Treatment of any underlying disease, such as chemotherapy if indicated for bone cancer, may help to improve the pain of a sternal fracture.

[citation needed] In 1864, E. Guilt published a handbook recording sternal fractures as a rare injury found in severe trauma.

[9] A rise in sternal fractures has also been seen with an increase in the frequency of laws requiring that seat belts be worn.