How does the hiccup cure work?

To cure hiccups, Andrew Huberman suggests a technique that involves hyperexciting the phrenic nerve to stop its spasming. Here's the method he describes:

1. Inhale deeply through your nose.
2. Without exhaling, take a second inhale through the nose.
3. Then, take a third, very brief inhale through the nose.
4. Hold your breath for 15-20 seconds.
5. Slowly exhale through the nose or mouth.

This unusual breathing pattern hyperexcites the phrenic nerve, causing it to undergo a hyperpolarization phase and thereby reducing its probability of activating again shortly after. This can effectively eliminate hiccups 1.

Understanding that hiccups are caused by spasms of the phrenic nerve, which controls the diaphragm, helps make sense of why this method works by targeting the nerve directly 2.