Question

If you hold your breath, what gas builds up in your blood

Answer 1

Carbon dioxide builds up in your blood

Answer 2

If you hold your breath, carbon dioxide builds up in your blood

The reason for this is:

When you exhale or breathe out, you exert or let out carbon dioxide. So, if you were to hold your breath, it would build up because it is not being exerted.


Hope this helped you!