an irregular slow, shallow pattern of alveolar ventilation which does not meet metabolic demands.

under-ventilation or under-breathing. Hypo- ventilation is always accompanied by an elevated carbon dioxide level in the blood.

very shallow respirations

Breathing at an abnormally shallow and slow rate.

Under-ventilation, when not enough air moves into and out of the lungs, and the arterial CO2 level increases

a slower-than-normal breathing rate

A state in which there is an insufficient amount of air entering and leaving the lungs to bring oxygen into tissues and eliminate carbon dioxide.

under breathing to the extent that the blood carbon dioxide level is elevated, may be manifested by carbon dioxide narcosis.

Reduced rate and depth of breathing.

Hypoventilation, or underventilation, is described by a decrease in alveolar ventilation relative to metabolic carbon dioxide production.

A respiratory rate that is insufficient to keep plasma PCO2 within normal levels.

Hypoventilation is the abnormally slow and shallow respiration, resulting in an increased level of carbon dioxide in the blood .

In medicine, hypoventilation (also known as "respiratory depression") occurs when ventilation is inadequate (hypo means "below") to perform needed gas exchange. It generally causes an increased concentration of carbon dioxide (hypercapnia) and respiratory acidosis. It can be caused by medical conditions, by holding one's breath, or by drugs.