eupné

Eupnée, also spelled eupnée, is the medical term for normal, quiet breathing at rest. The word derives from Greek eu- meaning "good" and pné meaning "breath." Eupnea describes a regular, effortless respiratory pattern with a normal rate and depth, without the use of accessory muscles or discomfort.

Physiology: In healthy adults, eupnea corresponds to a resting respiratory rate of roughly 12 to 20 breaths per minute and a tidal volume around 400–600 milliliters, yielding a minute ventilation of about 5–8 liters per minute. The breathing pattern is typically regular, with balanced inspiratory and expiratory phases and adequate gas exchange.

Clinical relevance: Eupnea is the baseline state of breathing in clinical assessment. Deviations include dyspnea (labored or difficult breathing), tachypnea (rapid breathing), bradypnea (slow breathing), and apnea (temporary cessation of breathing). Determining whether respiration is eupneic helps clinicians gauge respiratory function and detect distress or pathology.

Terminology and usage: The adjective form is eupneic, used to describe breathing that is normal and unlabored. In various medical contexts, eupnea serves as a reference point against which abnormal respiratory patterns are evaluated.

See also: respiration, dyspnea, tachypnea, bradypnea, apnea.