When you consume pungent spices like black pepper or green chillies, your body reacts to a group of chemical compounds including capsaicin, cryptocapsin, and capsicosin.
As these chemicals are released, they irritate the mucous membranes of the mouth and the esophagus (food pipe). This irritation can trigger a reflex that affects the phrenic nerve, which controls your diaphragm.
When the diaphragm’s normal rhythm is disrupted, it begins to contract and relax erratically or rapidly to expel the “irritated” air. As the diaphragm spasms, it causes you to suck in air quickly; when that air hits your voice box, your vocal cords close suddenly, creating the “hic” sound. This is essentially a homeostatic response—your body’s attempt to return to a stable internal state.


