One of the definitive conditions for ceasing hiccups is CO2 retention in the body, the target of which is around 60 mmHg of CO2 in venous blood. The fight-or-flight response induced by acute hypercapnia can effectively suppress hiccups because their original nature is highly likely to be aberrations in the swallowing reflex, which is associated with the parasympathetic nervous system.
Holding my breath works for me, or maybe it just passes the time. Usually goes away in about 2 full breaths.
Yeah. Oxygen deprivation releases the reflex, but you have to hold your breath, so long that it hurts.
There have actually been studies why that is.
Why is that?
https://journal.chestnet.org/article/S0012-3692(20)31301-5/fulltext
Doing a whip it cures hiccups