A<unk>  is a sleep<unk>  in which abnormalities in<unk>  occur during sleep that may or may not be present while awake. According to the International Classification of Sleep<unk> s,<unk> s are classified as follows: * Sleep apnea, including the more specific<unk> s of obstructive sleep apnea and central sleep apnea * Central hypoventilation syndromes * Obesity hypoventilation syndrome * Sleep-related hypoxemia<unk>  * Sleep-related hypoventilation due to a medication or substance, or due to a medical<unk>  * Isolated symptoms produced by<unk>  during sleep, including snoring and catathrenia.
Sleep-related breathing disorder
Sleep apnea
Central sleep apnea
Obstructive sleep apnea
Hyperventilation syndrome
Obesity hypoventilation syndrome
Shift work sleep disorder
Central hypoventilation syndrome