A Gasp Is the Body Demanding Air
To gasp is to catch the breath suddenly. The reflex is triggered by carbon dioxide, not by a lack of oxygen.
To gasp is to catch the breath suddenly, from shock, exertion or need for air. The urge to breathe is not triggered by falling oxygen but by rising carbon dioxide: receptors detect the acid it forms in the blood and force a breath. This is why hyperventilating before swimming underwater is dangerous — it lowers carbon dioxide so the warning never arrives, and a swimmer can lose consciousness without ever feeling short of breath. The word is Old Norse and imitative.
- To catch the breath. *She gasped aloud.*
- A sudden intake. *A gasp of surprise.*
- Last gasp — the final moment. *At the last gasp.*
- Gasping — struggling for air. *Gasping.*
- Old Norse — *geispa*, to yawn. *The source.*
Word forms
| Form | Word | Example |
|---|---|---|
| Verb | gasp | Gasping. |
| Noun | gasp | A gasp. |
| Past | gasped | Gasped. |
| Idiom | last gasp | The last gasp. |
| Old Norse | geispa | To yawn. |
- The crowd gasped at the news.Shock.
- He gasped for air.Exertion.
- Carbon dioxide drives the urge.Physiology.
Why the urge to breathe exists
- Carbon dioxide dissolves in blood and forms carbonic acid
- Receptors detect that acidity and trigger the urge to breathe
- Oxygen level is not the main signal
- Hyperventilating lowers carbon dioxide and delays the warning
- That is why it is dangerous before swimming underwater
Old Norse *geispa*, to yawn, of imitative origin, recorded in English from the 1300s.
What triggers the urge to breathe?
Rising carbon dioxide rather than falling oxygen. Receptors detect the acidity it creates in the blood.
Why is hyperventilating before diving dangerous?
It lowers carbon dioxide, so the urge to breathe is delayed and a swimmer may lose consciousness without any warning.