<unk>  is an abnormal pattern of breathing characterized by progressively deeper, and sometimes faster, breathing followed by a gradual decrease that results in a temporary stop in breathing called an apnea. The pattern repeats, with each cycle usually taking 30 seconds to 2 minutes. It is an oscillation of ventilation between apnea and hyperpnea with a crescendo-diminuendo pattern, and is associated with changing serum partial pressures of oxygen and carbon dioxide.<unk>  and periodic breathing are the two regions on a spectrum of severity of oscillatory tidal volume. The distinction lies in what is observed at the trough of ventilation:<unk>  involves apnea (since apnea is a prominent feature in their original description) while periodic breathing involves hypopnea (abnormally small but not absent breaths). These phenomena can occur during wakefulness or during sleep, where they are called the central sleep apnea syndrome (CSAS). It may be caused by damage to respiratory centers, or by physiological abnormalities in congestive heart failure, and is also seen in newborns with immature respiratory systems and in visitors new to high altitudes. One example is the breathing pattern in Joubert syndrome and related disorders.
Cheyne–Stokes respiration
Ataxic respiration
Auscultatory gap
Pursed-lip breathing
Autoinflation
Bronchial hyperresponsiveness
Dispokinesis
Bio-secure bubble