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Low oxygenation plays a role in embryonic development and may be physiologically normal for some adult tissues which maintain a hypoxic environment (e.g., bone marrow microdomains and thymus). However, oxygen deficiency commonly affects cellular function and disrupts various biological processes, including cell proliferation and differentiation, angiogenesis, metabolism, and pH homeostasis. 

Hypoxia Research Product Areas 


Hypoxia Detection Methods  Hypoxia Inducers & Inhibitors

Hypoxia Signaling

Hypoxia Inducible Factors



Physiologic Median O2 Levels in Organs and Tissues

Median O2 Levels in Human Organs and Tissues

Defining Hypoxia States*

Cellular responses to hypoxia are critically dependent on the duration (acute vs chronic) and extent (hypoxia vs anoxia) of the low-oxygen state, and are predominantly mediated by hypoxia-inducible factors (HIFs), considered to be “master regulators” of adaptations to low-oxygenation. However, both HIF-dependent and -independent mechanisms play roles in shaping cellular responses to hypoxia in physiology and disease.

Duration Extent
Low tissue oxygen from minutes to hours, due to temporary limitations in blood flow
~ 1-2% O2
Low tissue oxygen from hours to days, due to limitations in the diffusion of oxygen to distant tissues
~ 0.02% O2 and below

*Definitions for hypoxia are based on conditions used in cancer model systems.