Shortness of breath or difficulty in breathing is also called dyspnea and can be acute or chronic. It has various causes, but mainly can be caused by a problem in the heart or the lungs. Since your heart and lungs are both involved in the transportation of the oxygen to the tissues and the removal of carbon dioxide, any problems occurring to these systems can affect breathing.
B-type Natriuretic Peptide (BNP) reflect the systolic and diastolic activity of the heart and its blood levels can show any heart failure. A BNP test and can help the nurse decide whether the cause of the dyspnea is a heart failure or some respiratory problem.