hypoxia

Etymology

It is formed from English hypo- + oxygen + -ia.^{[2][3][4][5][6]} The OED and Merriam-Webster analyse the middle part as ox-, the combining form taken from oxygen;^[7][8] Merriam-Webster treats the word as New Latin.^[8]

Earliest recorded meaning

A deficiency of oxygen in the tissues of the body: 1941, in the Annals of Internal Medicine.^[7][8][2]

Semantic evolution

The word belongs to 20th-century medicine.^[6][3] The OED defines it simply as equivalent to anoxia,^[7] while Stedman's medical dictionary distinguishes the two: hypoxia is a fall below the normal level of oxygen in inspired air, arterial blood or tissue that stops short of anoxia.^[5] Merriam-Webster includes both a shortage of oxygen in the surroundings and a failure of the breathing or circulation to deliver it.^[8] Wiktionary also records a use in ecology, for a low level of dissolved oxygen in water.^[1] The adjective hypoxic is formed alongside it.^[2][6][8]

Timeline

• 1941 – a deficiency of oxygen reaching the body's tissues.^[7][8][2]

Meanings

Noun

1. A deficiency in the amount of oxygen reaching the tissues of the body, whether from a shortage in the air breathed or from a fault in the respiratory or circulatory system: Climbers above 8,000 metres risk hypoxia.^[8][6][9]
2. (medicine) A drop in the oxygen level of inspired gases, arterial blood or tissue below normal, short of anoxia.^[5]
3. A reduced level of dissolved oxygen in a body of water.^[1]

Word family

• hypoxic

Related words

• hypoxemia
• anoxia
• oxygen

References

1. ^ a b c Wiktionary, the free dictionary, https://en.wiktionary.org
2. ^ a b c d Harper, Douglas. Online Etymology Dictionary, https://www.etymonline.com
3. ^ a b Stevenson, Angus, ed. (2010), Oxford Dictionary of English, 3rd ed., Oxford: Oxford University Press
4. ^ Soanes, Catherine; Stevenson, Angus, eds. (2004), Concise Oxford English Dictionary, 11th ed., Oxford: Oxford University Press
5. ^ a b c Stedman's Medical Dictionary, Baltimore: Lippincott Williams & Wilkins
6. ^ a b c d Collins English Dictionary (2023), Glasgow: HarperCollins
7. ^ a b c d Oxford English Dictionary Online (accessed March 2026), Oxford: Oxford University Press
8. ^ a b c d e f g Merriam-Webster Unabridged Dictionary (2024), online ed., Springfield, Mass.: Merriam-Webster
9. ^ The American Heritage Dictionary of the English Language (1992), 3rd ed., Boston: Houghton Mifflin