Introduction Everyone has experienced hiccups—those sudden, involuntary “hic” sounds that can strike without warning. While usually harmless, hiccups are often puzzling and sometimes embarrassing. But what exactly causes them? To understand hiccups, we need to look closely at how the diaphragm, nervous system, and reflex pathways work together. The Role of the Diaphragm The diaphragm is a dome-shaped muscle located just below the lungs. It plays a vital role in breathing: A hiccup occurs when the diaphragm suddenly and involuntarily spasms, causing a quick intake of air. Almost immediately, the vocal cords close, producing the distinctive “hic” sound. The Hiccup…