Associated with asthma and emphysema and angina pectoris

• Form of dyspnea in which the person can breathe comfortably only when standing or sitting erect

WordNet Word definitions in WordNet
n. form of dyspnea in which the person can breathe comfortably only when standing or sitting erect; associated with asthma and emphysema and angina pectoris

Wikipedia Word definitions in Wikipedia
Orthopnea or orthopnoea ( Greek from ortho , straight + pnoia , breath) is shortness of breath ( dyspnea ) that occurs when lying flat, causing the person to have to sleep propped up in bed or sitting in a chair. It is commonly seen as a late manifestation ...

Wiktionary Word definitions in Wiktionary
n. (alternative spelling of orthopnoea English)