Excess neck fat acts like a “noose,” compressing the airway. At night, relaxed muscles cause repeated airway collapse: breathing pauses hundreds of times nightly, up to 50 seconds each — repeated cycles of hypoxia → suffocation → awakening. This intermittent nighttime hypoxia: Raises heart workload，Triggers sympathetic overactivity，Causes nocturnal hypertension and arrhythmias，Increases sudden‑death risk.