What is the term for dyspnea triggered by assuming the upright position?

The term for dyspnea triggered by assuming an upright position is known as platypnea. This condition is characterized by difficulty breathing that occurs specifically when a person is standing or sitting upright, and typically improves when lying down. It is often associated with certain medical conditions that affect the circulatory or respiratory systems, such as heart diseases or lung pathologies, where the dynamics of blood flow and gas exchange can lead to temporary respiratory distress in specific postures.

In contrast, orthodeoxia refers to a drop in oxygen saturation that occurs when a patient is sitting or standing up, but it does not specifically relate to the sensation of dyspnea as platypnea does. Cough is a reflex action to clear the throat or airways of irritants, and hemoptysis refers to coughing up blood or blood-stained sputum, neither of which describe a positional dyspnea.