Plain English Meaning
A feeling that you can't get enough air, or that breathing is taking real effort. It's the sensation of struggling to breathe, even when you're trying to breathe normally.
Full Definition
Difficult or labored breathing, often felt as shortness of breath or air hunger. In aviation medicine, it is a recognized symptom of decompression sickness, hypoxia, and other altitude-related conditions affecting the lungs or oxygen delivery.
Context Anchor
Seen in altitude-related medical symptoms, including the FAA discussion of altitude-induced decompression sickness.
Derivation
From Greek 'dys-' meaning bad or difficult, and 'pnoe' meaning breathing. So literally 'bad breathing.' Knowing the 'dys-' prefix (as in dysfunction) helps lock in that this is breathing gone wrong, not just being out of breath from exertion.
Why Pilots Care
Recognizing dyspnea signals possible hypoxia or DCS, prompting immediate use of oxygen or descent.