Cells need oxygen to function and clearly the cells in a zombie are at least partly functional. In the Walking Dead, do zombies need oxygen? Can they breathe? If they don't have functional respiratory or circulatory systems, do they absorb some oxygen through exposed tissue?

Related: In Walking Dead (TV), how do zombies walk without blood circulating?

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    Down-voted due to lack of research effort: Several times in the series, it is shown that zombie heads are still active when separated from their bodies (so long as substantial damage has not been done to the brain) - even when kept underwater for extended periods.
    – Iszi
    Mar 3, 2014 at 22:45
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    @Iszi: This is the makings of an answer, not a reason to downvote due to "lack of research effort" ! Mar 7, 2014 at 16:44
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    The tooltip for the down-vote button explicitly states "does not show any research effort" as a valid reason for its use.
    – Iszi
    Mar 7, 2014 at 16:50
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    @Iszi: Show me how you "research" that without sitting down and watching every episode. Seriously. "Does not show research effort" doesn't mean "OP isn't an expert so let's downvote" Mar 7, 2014 at 17:26
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    @ThePopMachine have you seen the show?
    – Daft
    Feb 25, 2015 at 16:35

5 Answers 5


TL;DR: No, zombies don't need oxygen to survive. We don't know how zombie physiology works, but we know that they don't breathe.

In fact, we've seen a number of walkers surviving long periods of time underwater.

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And at least one buried (but still active) walker.

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It has also been established that a severed zombie head remains active unless the brain is destroyed. This is relevant, because obviously, severed heads don't have lungs attached to them.

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The zombies in The Walking Dead don't need to do anything, really. They don't need to breathe, as these gifs show, and they also don't need to eat, despite the fact that they do so all the time. Their respiratory and digestive systems are rotten and useless. They can't breathe, and they can't digest anything. Since they can't do these things, obviously they also don't need to do them.


No. In pretty much any mythology (at least where zombies are dead, not living 'infected') zombies do not need to breathe at all. There is no explanation given for how they function without oxygen, nor is there an explanation for where the energy they use comes from.

Zombies have been seen to operate just fine underwater for extended periods, and zombie heads are still animate (unless the brain is destroyed) even without lungs. It is probable that a zombie could function in a vacuum, unless they were frozen stiff.

This is, frankly, a conceit of the genre. There's no real explanation, and I don't think there can be one. We do, however, know that they don't need oxygen to function.

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    Zombies...in...SPAAAAAAAACE!!!! I'd watch that.
    – Monty129
    Mar 3, 2014 at 17:59
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  • @GorchestopherH well played.
    – Monty129
    Mar 3, 2014 at 21:32
  • There is no scientific explanation. A supernatural one is perfectly consistent. People assume that the contagious nature indicates a pathogen, but this is almost besides the point. It is not that the bite spreads a disease, but rather that it defiles the victim enough that they too become susceptible to the supernatural effect.
    – John O
    Mar 4, 2014 at 5:37
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    The particular example I remember (from the comics) is the Governor keeping a collection of zombie heads in water-filled jars in his home, watching them move around like you would watch TV. Feb 25, 2015 at 21:27

Why do you assume their cells to be functional? In fact, in every single zombie representation I am aware of zombies don't heal. If their cells were working, I'd expect them to have normal healing powers but generally, when you cut a zombie, the cut stays open and you get those wonderfully gruesome images that so enhance our viewing pleasure.

So, while no explanation is given in any canon I know, the fact that they don't heal would point to their being animate but non-living tissue (whatever that may mean) and as such I would not expect them to need or use oxygen, no.

  • Agreed, zombie cells don't heal, but they can still be partly functional. Which was OPs point. And a pretty decent assumption, considering the fact that zombies move. Movement in humans is induced by contractions in muscle cells, thus zombies need at least partly functioning cells in order to move.
    – thomax
    Mar 3, 2014 at 19:20
  • @thomax actually, and I realize I'm being pedantic, muscle cells can contract even in dead tissue, a classic example is pouring soy sauce on a dead octopus. It is a matter of electricity and does not need any living cells.
    – terdon
    Mar 3, 2014 at 19:30
  • Sure, zombie cells aren't neccessarily alive. However, a contracting muscle cell is fulfilling it's primary objective: generating movement. It doesn't matter if this movement is fueled by ATP, soy sauce or magic. It's hard to argue that a jerking muscle cell is not at least partly functional.
    – thomax
    Mar 3, 2014 at 19:42
  • Zombies don't use their muscles to move. Zombies are powered magically by evil negative energy. In this respect, they work the same way as skeletons, which are just zombies where most of the body is gone and only the bones remain, or ghosts which are like zombies where no parts of the body remains.
    – b_jonas
    Mar 3, 2014 at 19:50
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    @thomax lol :). Anyway, the onus would be on you to demonstrate that zombie movement actually involves contracting muscles, else you'll need to defend yourself from zombie Popper.
    – terdon
    Mar 3, 2014 at 20:06

Just enjoy the ride. Zombie animation makes no sense at all. Especially in severely decayed or damaged state. Abdominals and disemboweled yet they still walk. They don't breathe yet they make guttural noises from the mouth. Can't be explained, but great TV and drama.

  • We generally look for in-universe reasons for answers and not just what a user has experienced out of universe. Is there any in-universe information you can provide?
    – Edlothiad
    Oct 24, 2017 at 5:28

It's obviously all fiction but interesting speculation. The CDC pictures showed brain stem activity so function was to some degree physical/organic. It would seem for even the stem to function there would have to be oxygen/nutrients/etc. I even remember one episode someone saying they do starve but slower than us. It seems they need to consume flesh and this is driven by base instincts from the brain stem. It also seems inconsistent that puncturing the brain up high(chopping top of head off/eye piercing would be effective since it showed clearly at CDC that only base of brain/stem had any activity.

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