What does hypoxia mean?
Hypoxia is the medical term for a condition in which the body or its tissues do not receive or use enough oxygen. It can result from low oxygen levels in the environment, such as at high altitude or underwater, or from problems involving breathing, circulation, or the blood’s ability to carry oxygen. Hypoxia is broader than anoxia, which refers to a complete absence of oxygen, and is related to asphyxia, which specifically involves suffocation or obstruction of breathing. In medicine, clinicians may distinguish between different forms according to the affected tissues or the underlying cause. The word is also used in figurative contexts for severe lack of oxygen, but its primary sense is scientific and clinical. Recognizing hypoxia matters because insufficient oxygen can rapidly impair the brain, heart, and other vital organs, making it an important concern in emergency care, aviation, diving, and high-altitude medicine.
nounA condition in which the body or a body tissue receives or uses insufficient oxygen. It may result from inadequate oxygen in the environment, impaired breathing or circulation, or other medical causes.
- A condition in which the body or a body tissue receives or uses insufficient oxygen.
"The climber developed altitude hypoxia before reaching the summit."
"Early oxygen therapy helped prevent tissue hypoxia in the injured patient."
"The report describes a gradual increase in hypoxia as the aircraft climbed to high altitude."
The plural is used when referring to separate cases of the condition.
"The study compared hypoxias caused by lung disease with those caused by severe anemia."
Hypoxia can occur even when someone is breathing: oxygen may be present in the air yet remain unavailable to the body’s tissues because circulation or cellular use is impaired.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does hypoxia come from?
The word was formed in the 19th century from the combining form hypo-, meaning “under” or “below,” and oxy-, the element associated with oxygen. Oxy- in turn comes through the English word oxygen from Greek oxys, meaning “sharp” or “acute,” in reference to the acid-forming properties of oxygen. The medical term developed alongside the broader scientific vocabulary for oxygen and its compounds.
Related word forms
How hypoxia is actually used
This is primarily a medical and scientific term. In general writing, it often denotes a serious medical condition, while “altitude hypoxia” specifically refers to oxygen deficiency caused by high altitude.
Easily confused with hypoxia
Hypoxia means insufficient oxygen availability or use, whereas anoxia means a complete absence of oxygen.
Asphyxia is suffocation or oxygen deprivation caused by a blockage or failure of breathing, while hypoxia is the broader condition of inadequate oxygen supply or utilization.