Any process that results in a change in state or activity of a cell or an organism (in terms of movement, secretion, enzyme production, gene expression, etc.) as a result of a stimulus indicating lowered oxygen tension. Hypoxia, defined as a decline in O2 levels below normoxic levels of 20.8 - 20.95%, results in metabolic adaptation at both the cellular and organismal level. [ GOC:hjd ]
Synonyms: response to lowered oxygen tension response to hypoxic stress
Term information
Note that this term should not be confused with 'response to anoxia ; GO:0034059'. Note that in laboratory studies, hypoxia is typically studied at O2 concentrations ranging from 0.1 - 5%.