According to WebMD, pain in the back and right shoulder blade upon breathing can signify a heart attack, so it is important to consult a physician if the pain is accompanied by nausea, dizziness, rapid heartbeat or shortness of breath. WebMD notes that severe back pain can also indicate a spinal cord injury. Additional symptoms include numbness and tingling in the arms and severe neck pain.
MedlinePlus explains that pain in the back and shoulders upon breathing is also a common symptom of stable angina, a condition caused by inadequate blood flow of the heart vessels. It's important for individuals with symptoms of angina to consult with a physician, as angina is often accompanied by blood clots that occur when the heart arteries become hardened. Additional signs of angina include pain in the neck and jaw, shortness of breath, weakness and fatigue. Angina attacks often occur after strenuous activities or periods of high stress.
The Mayo Clinic explains that scoliosis, a condition that causes a curvature of the spine, can cause severe back pain and breathing difficulty. Severe curvatures can cause the spine to twist, which in turn causes the ribs to protrude on one side of the body. The specific cause of scoliosis is unknown, but it's linked to spinal cord injuries and birth defects that affect spinal development.