Anoxia, or a lack of oxygen in bodies of water, leads to

irreversible brain damage and death

Explanation:

    Anoxia is a condition characterized by a lack of oxygen in the brain, which can lead to the death of neurons and result in irreversible brain damage. Anoxia can happen due to bleeding or respiratory arrest, for example, and the longer the brain is left without oxygen, the more severe the consequences.

    The severity of the injury is also related to the region of the brain that has no oxygen supply. As the central nervous system hardly regenerates, the lesions may be permanent.