The Airway Is a Tunnel, and Some Tunnels Are Narrower to Begin With
The throat does not stay open on its own during sleep. Muscle tone holds it. When that tone drops, as it does in deep sleep, the walls of the airway depend on the space around them. A jaw that sits further back relative to the skull, a palate that arches higher, or a tongue that is proportionally large for the oral cavity all reduce that space before a single kilogram of fat is added. These are structural facts, not pathologies. They vary across populations, and several studies from the All India Institute of Medical Sciences and from craniofacial research groups in Chennai and Pune have documented that average jaw retrusion and palatal height differ measurably between South Asian and European populations. The airway in a person with these features has less room to give before it collapses.
