Hypobaric vs Hypoxia - What's the difference?

As an adjective hypobaric

is of, relating to, or utilizing less than normal pressure (as in air pressure).

(pathology) a condition in which tissues (especially the blood) are deprived of an adequate supply of oxygen; anoxia.

(en adjective)

Of, relating to, or utilizing less than normal pressure (as in air pressure).

Mountain climbers need additional oxygen because of the hypobaric conditions

* hyperbaric

(wikipedia hypoxia)

(pathology) A condition in which tissues (especially the blood) are deprived of an adequate supply of oxygen; anoxia

A reduced concentration of dissolved oxygen in an aquatic environment.

* hypoxic