What is "hypoxia"

1941, from hypo- + oxygen + abstract noun ending -ia. Related: Hypoxic.

n. 1 (context pathology English) A condition in which tissues (especially the blood) are deprived of an adequate supply of oxygen; anoxia 2 A reduced concentration of dissolved oxygen in an aquatic environment.

n. a very strong drive resulting from a deficiency of available oxygen in the blood and bodily tissues (short of anoxia)

Hypoxia (also known as hypoxiation) is a condition in which the body or a region of the body is deprived of adequate oxygen supply at the tissue level. Hypoxia may be classified as either generalized, affecting the whole body, or local, affecting a region of the body. Although hypoxia is often a pathological condition, variations in arterial oxygen concentrations can be part of the normal physiology, for example, during hypoventilation training or strenuous physical exercise.

Hypoxia differs from hypoxemia and anoxemia in that hypoxia refers to a state in which oxygen supply is insufficient, whereas hypoxemia and anoxemia refer specifically to states that have low or zero arterial oxygen supply. Hypoxia in which there is complete deprivation of oxygen supply is referred to as anoxia.

Generalized hypoxia occurs in healthy people when they ascend to high altitude, where it causes altitude sickness leading to potentially fatal complications: high altitude pulmonary edema ( HAPE) and high altitude cerebral edema ( HACE). Hypoxia also occurs in healthy individuals when breathing mixtures of gases with a low oxygen content, e.g. while diving underwater especially when using closed-circuit rebreather systems that control the amount of oxygen in the supplied air. A mild and non-damaging intermittent hypoxia is used intentionally during altitude trainings to develop an athletic performance adaptation at both the systemic and cellular level.

Hypoxia is also a serious consequence of preterm birth in the neonate. The main cause for this is that the lungs of the human fetus are among the last organs to develop during pregnancy. To assist the lungs to distribute oxygenated blood throughout the body, infants at risk of hypoxia are often placed inside an incubator capable of providing continuous positive airway pressure (also known as a humidicrib).

Hypoxia may refer to:

• Hypoxia (environmental), reduced oxygen content of air or a body of water detrimental to aerobic organisms
• Hypoxia (medical), a pathological condition in which the body or a region of the body is deprived of an adequate oxygen supply
  • Autoerotic hypoxia or erotic asphyxiation, intentional restriction of oxygen to the brain for sexual arousal
  • Cerebral hypoxia or cerebral anoxia, a reduced supply of oxygen to the brain
  • Diffusion hypoxia or Fink effect, a factor that influences the partial pressure of oxygen within the pulmonary alveolus
  • Histotoxic hypoxia, the inability of cells to take up or utilize oxygen from the bloodstream
  • Hypoxemic hypoxia or hypoxemia, a deficiency of oxygen in arterial blood
  • Hypoxia drive, a respiratory drive in which the body uses oxygen chemoreceptors to regulate the respiratory cycle
  • Hypoxic hypoxia, a result of insufficient oxygen available to the lungs
  • Intrauterine hypoxia, when a fetus is deprived of an adequate supply of oxygen
  • Latent hypoxia or deep water blackout, loss of consciousness on ascending from a deep freedive
  • Pseudohypoxia, increased cytosolic ratio of free NADH to NAD in cells
  • Tumor hypoxia, the situation where tumor cells have been deprived of oxygen
• Hypoxia in fish, responses of fish to hypoxia

Hypoxia refers to low oxygen conditions. Normally, 20.9% of the gas in the atmosphere is oxygen. The partial pressure of oxygen in the atmosphere is 20.9% of the total barometric pressure. In water however, oxygen levels are much lower, approximately 1%, and fluctuate locally depending on the presence of photosynthetic organisms and relative distance to the surface (if there is more oxygen in the air, it will diffuse across the partial pressure gradient).

Hypoxia is Kathryn Williams 12th album and was released by One Little Indian on 15 June 2015. The songs were initially conceived as a result of a 2013 writing commission from New Writing North in conjunction with the Durham Book Festival's 50th anniversary celebration of the publication of Sylvia Plath's 'The Bell Jar' novel.

Kathryn performed five songs at the festival and completed writing the project whilst touring her 'Crown Electric' release. "So I was writing the songs in Travelodges and on the side of the A1 in between gigs. Those were some dark days with only the sound of the motorway and a Little Chef to drown my sorrows in,"

The Scottish Herald wrote the album was "a collection of rare eloquence and spectacular beauty" with Clash Magazine concluding "By inhabiting and responding to a genuinely significant work of literature, Williams has produced her own spellbinding work of art"