Exertional Dyspnea

Shortness of breath during exercise (exertional dyspnea) produces a sensation of not being able to "get enough air" and a feeling of being "out of breath."  A number of factors can cause exertional dyspnea, but they are usually related to insufficient tissue oxygenation by the blood.  This usually results from impaired oxygen exchange by the lungs and can be caused by pulmonary edema or by insufficient blood being pumped by the heart to the lungs and peripheral organs during exertion (i.e., reduced tissue perfusion).  Therefore, a very common cause of exertional dyspnea is heart failure, which results in both impaired perfusion (reduced cardiac output) and, in some types of failure, elevations in pulmonary capillary pressure leading to pulmonary edema.

RK Revised 04/06/07