List of terms of lung size and activity
# List of terms of lung size and activity

Following are terms that specify a type of lung size and/or activity. More specific definitions may be found in individual articles.

* Eupnea – normal breathing
* Apnea – absence of breathing
* Bradypnea – decreased breathing rate
* Dyspnea or shortness of breath – sensation of respiratory distress
* Hyperaeration/Hyperinflation – increased lung volume
* Hyperpnea – fast and deep breathing
* Hyperventilation – increased breathing that causes $CO_2$ loss
* Hypopnea – slow and shallow breathing
* Hypoventilation – decreased breathing that causes $CO_2$ gain
* Labored breathing – physical presentation of respiratory distress
* Tachypnea – increased breathing rate
* Orthopnea – Breathlessness in lying down position relieved by sitting up or standing
* Platypnea – Breathlessness when seated or standing, relieved by lying flat
* Trepopnea – Breathlessness when lying flat relieved by lying in a lateral position
* Ponopnea – Painful breathing
