altitude sickness

noun

: the effects (such as headache, nausea, or swelling of the brain) of oxygen deficiency in the blood and tissues developed at high altitudes having reduced atmospheric pressure see mountain sickness

Examples of altitude sickness in a Sentence

Recent Examples on the Web

This gondola journey to Punta Helbronner, about 11,000 feet high, is not for the faint of heart—altitude sickness is real. —Hannah Howard, Travel + Leisure, 16 Aug. 2025

Low oxygen levels at this altitude may cause altitude sickness or breathing problems, so acclimatization is essential. —Kathleen Peddicord, Forbes.com, 30 June 2025

During their 19-hour hike, Ryan said his son began showing signs of altitude sickness, according to NBC affiliate KSNV. —Charlotte Phillipp, People.com, 29 June 2025

Talk about some of the challenges of the race, including potentially altitude sickness. —Morgan Korn, ABC News, 21 June 2025

Word History

First Known Use

1901, in the meaning defined above

Rhymes for altitude sickness

• homesickness
• seasickness
• quickness
• thickness

Medical Definition

altitude sickness

noun

al·​ti·​tude sickness ˌal-tə-ˌt(y)üd- 

: the effects (as nosebleed, nausea, headache, or cerebral edema) of oxygen deficiency in the blood and tissues developed at high altitudes with reduced atmospheric pressure