A 29-year-old member asked:
How long does it take before brain damage occur from lack of oxygen to the brain?
1 doctor answer • 4 doctors weighed in
Radiology 47 years experience
4 minutes or more: In the event of a full blown cardiac arrest there can be brain damage in as little as 4 to 5 minutes without circulation at normal body temperature. If the body had been cooled by submersion in cold water it could be much longer. Less severe lack of oxygen will take longer to produce brain damage.
5.5k viewsReviewed >2 years ago
A 32-year-old member asked:
Can you get brain damage from lack of oxygen fainting?
2 doctor answers • 5 doctors weighed in
Neurosurgery 54 years experience
Yes: The human brain can withstand at most 4 minutes of oxygen deprivation before experiencing brain damage. Damage may be irreversible at this time but the brainstem is more resistant, hence the occurrence of "persistent vegetative state". But a simple faint can result from only a few seconds of oxygen deprivation without causing long-term damage.
6k viewsReviewed >2 years ago
Last updated Oct 28, 2018
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