The consequences of sleep-related hypoventilati on are related to the effects of chronic ex-
posure to hypercapnia and hypoxemia. Th ese blood gas derangements cause vasocon-
striction of the pulmonary va sculature leading to pulmon ary hypertension, which, if
severe, can result in right-sided heart failure  (cor pulmonale). Hypo xemia can lead to dys-
function of organs such as the brain, blood,  and heart, leading to outcomes such as cog-
nitive dysfunction, polycythemia, and cardiac arrhythmias. Hypercapnia can depress
ventilatory drive, leading to pr ogressive respiratory failure. 
Differential Diagnosis
Other medical conditions affecting ventilation. In adults, the idiopathic variety of sleep-
related hypoventilation is very uncommon and is determined by excluding the presence of
lung diseases, skeletal malformations, neuromuscular disorders, and other medical and
neurological disorders or medications that affect ventilation. Sleep-related hypoventila-
tion must be distinguished from other causes of sleep-related hypoxemia, such as that due
to lung disease.
Other breathing-related sleep disorders. Sleep-related hypoventilation can be distin-
guished from obstructive sleep  apnea hypopnea and central sleep apnea based on clinical
features and findings on polysomnography. Sl eep-related hypoventilation typically shows
more sustained periods of oxygen desaturation rather that  the periodic episodes seen in
obstructive sleep apnea hypopnea and central sleep apnea. Obstructive sleep apnea hy-
popnea and central sleep apnea also show a pa ttern of discrete epis odes of re peated air-
flow decreases that can be absent in sleep-related hypoventilation.
Comorbidity