Orthopnoea

Part of speech: noun

Pronunciation: /ɔrˈθɒpniə/

Definitions

1. A pathological state where an individual struggles to breathe while in a horizontal position
2. A medical condition causing shortness of breath specifically when lying down
3. Experience of breathlessness triggered by reclining or lying in a supine position

Etymology: Orthopnoea describes breathlessness that gets worse when a person lies flat and eases when they sit or stand upright. The Greek word it was built from, "orthopnoia", literally meant "breathing only in an upright posture", and the description was coined from exactly that observation about the patient's body. The term is made of two Greek parts. "Orthos" means "straight" or "upright", the same root that gives English "orthodox" and "orthopaedic", and "pnoe" means "breath", which also appears in words like "dyspnoea", meaning difficult or laboured breathing. Put together, the word describes a symptom defined by a body position rather than by a disease, which is why it sits at the heart of how clinicians describe heart and lung failure.