Collarbone pain when a person breathes could be caused by lung disorders or pneumonia; these conditions typically also include shortness of breath and coughing, according to Dr. John C. Wolf with the Ohio University College of Osteopathic Medicine. Arthritis can cause collarbone pain as well.
When a patient experiences arthritis in the shoulder or joints at the end of the collarbone, pain of a grinding sensation typically occurs, explains Dr. Wolf. Disorders within muscles or bones near the collarbone can also cause pain when a person breathes. For example, when these muscles are weak or injured, the muscles move the ribs when a person breathes; the strain of rib movement causes pain under the collarbone.
Heart conditions, such as heart disease or problems associated with the smaller blood vessels near the heart that connect with the subclavian artery that branches to the arm, can cause collarbone pain when a person breathes. Infections within the vessels produces discomfort, notes Dr. Wolf. A blockage within the arteries is assessed through an electrocardiogram stress test, whereas arthritis, bone or muscle problems are evaluated through X-rays.
A broken collarbone causes pain when a person breathes, but this type of injury is typically accompanied by an inability to lift the arm, immediate pain after a fall or injury and a constant grinding sensation, according to WebMD.