The causes of upper back pain when breathing are numerous. Infections, injuries, and heart issues are among them. A person may desire to seek medical assistance if the cause is not clear. When it comes to breathing, upper back discomfort might be a sign of a significant health problem. When breathing, pain in the upper back generally radiates around the chest. Pleurisy or a heart attack can both cause severe discomfort. A broken vertebra or a muscular strain might cause dull pain.