<unk>  <unk>  is a sleep-related breathing disorder that causes ineffective breathing, apnea, or respiratory arrest during sleep (and during wakefulness in severe cases).<unk>  can either be congenital (CCHS) or acquired (ACHS) later in life. The condition can be fatal if untreated. CCHS was once known as Ondine's curse. ACHS can develop as a result of severe injury or trauma to the brain or brainstem. Congenital cases are very rare and involve a failure of autonomic control of breathing. In 2006, there were only about 200 known cases worldwide. As of 2008, only 1000 total cases were known. The diagnosis may be delayed because of variations in the severity of the manifestations or lack of awareness in the medical community, particularly in milder cases. However, as there have been cases where asymptomatic family members also were found to have CCHS, it may be that these figures only reflect those found to require mechanical ventilation. In all cases, episodes of apnea occur in sleep, but in a few patients, at the most severe end of the spectrum, apnea also occurs while awake. Although rare, cases of long-term untreated CCHS have been reported and are termed late onset CCHS (LO-CCHS). There have, however, even been cases of LO-CCHS where family members found to have it have been asymptomatic. Again, lack of awareness in the medical community may cause such a delay. CCHS susceptibility is not known to be affected by sex or race.
Central hypoventilation syndrome
Obesity hypoventilation syndrome
Hyperventilation syndrome
Upper airway resistance syndrome
Sleep apnea
Reactive airway disease
Central sleep apnea
Cardiac asthma