Which factor is primarily responsible for exertional dyspnea?

Exertional dyspnea refers to shortness of breath that occurs during physical activity. The primary factor responsible for this condition is increased pulmonary vascular resistance. When the pulmonary vasculature experiences resistance, it can impair blood flow, leading to increased pressure in the vessels and reduced oxygenation of the blood. This can cause the body to struggle to meet its oxygen demands during exertion, leading to feelings of breathlessness.

Increased pulmonary vascular resistance may be caused by conditions such as pulmonary hypertension or other cardiovascular issues leading to inadequate blood flow through the lungs. This inadequate perfusion means that even if the individual is attempting to take in more air and increase oxygen intake, the physiological response is compromised due to issues in the pulmonary circulation.

Understanding exertional dyspnea in the context of increased pulmonary vascular resistance is crucial for recognizing how various cardiovascular and respiratory conditions contribute to the symptoms experienced by patients during physical activity.