#1 – How do hiccups happen?
When you breathe in, your diaphragm pushes downward to draw air into your lungs and when you exhale, the diaphragm pushes upward to expel air.
Hiccupping occurs as your diaphragm draws in air between the breaths you take, causing it to spasm in order to prevent more air from rushing into your lungs, and the vocal cords to suddenly close which results in hiccups.
Hiccups are usually harmless and go away after a few minutes. But sometimes they can be caused by medications or serious health issues.