What is pain under the left breast with back pain on the left and right side. lungs are clear short breaths.

This : This pain could be from a cardiac cause, such as heart pain. Cardiac pain is usually worse with activity, is more common in patients with cardiovascular risk factors such as high cholesterol, smoking, or hypertension. Lung causes such as pleurisy or blood clot are a possibility but then usually the pain is worse with deep breathing. Abdominal causes such as pancreatitis or gallstones could also cause upper abdominal/chest pain. If your pain has persisted, if you have nausea/vomiting, fever, or the symptoms stated above then please go to the er.