eupnea

Eupnea is ordinary, comfortable breathing — the easy in-and-out you do right now without noticing. It is breathing at rest done well: regular in rhythm, even in depth, quiet, and requiring no obvious effort.

The word comes from Greek roots meaning good breathing, and it serves as the baseline that doctors compare other breathing patterns against. In eupnea an adult takes around 12 to 20 breaths a minute, each moving a normal tidal volume, with the diaphragm doing most of the work and the accessory neck and shoulder muscles staying relaxed.

Eupnea is the calm reference point for a whole family of named abnormal patterns — fast (tachypnea), slow (bradypnea), laboured or air-hungry breathing (dyspnea), and the cyclical or irregular patterns seen in serious illness. Noticing that breathing is no longer eupneic is often the first clue at the bedside that something is wrong.