Oxygen deficiency in body tissue.
A distinction can be made between respiratory H. (due to disturbances in oxygen uptake via the lungs), circulatory H. (due to insufficiency in the distribution of oxygen-rich blood), anaemic H. (due to lack of transportable haemoglobin) and histotoxic H. (due to disturbance or poisoning of cell respiration).
https://de.wikipedia.org/wiki/Hypoxie_(Medicine) (Wikipedia CC-by-sa-3.0)