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. Hypoventilation may be dangerous for those with sleep apnea.

As a side effect of recreational drugs, hypoventilation may become potentially life-threatening. Heroin is notorious for this effect; in an overdose, an individual may cease breathing (go into respiratory arrest).

A disorder referred to as "Congenital Central Hypoventilation Syndrome" or "CCHS" is recognized.

The opposite condition is hyperventilation, which is caused by too much ventilation resulting in low carbon dioxide levels. It leads to hypocapnia rather than hypercapnia.

See also

• Dyspnea

Symptoms | Pulmonology

Hypoventilation | Hypoventilation