Snoring & Treatment Glossary of Terms

AHI abbr. apnea-hypopnea index

apnea Cessation of airflow at the nostrils and mouth lasting at least 10 seconds. There are three types of apnea. Obstructive apnea is secondary to upper airway obstruction. Central apnea is associated with cessation of all respiratory movements. Mixed apneas have both central and obstructive components.

bilevel CPAP A variation of CPAP where the inspiratory positive airway pressure (IPAP) is usually higher than the expiratory positive airway pressure (EPAP).

BMI abbr. body mass index. BMI is calculated by dividing a person’s weight in kg by the person’s height in meters squared. Adults whose BMI exceeds 27 kg/m2 are considered to be overweight.

central sleep apnea Cessation of airway at the nostrils and mouth lasting at least 10 seconds due to cessation of all respiratory movements.

circadian rhythm A biological rhythm that has a period length of about 24 hours.

CPAP abbr. continuous positive airway pressure

EDS abbr. excessive daytime sleepiness

EEG abbr. electroencephalography

EOG abbr. electro-oculography

ESS abbr. Epworth sleepiness scale

hypopnea Episode of shallow breathing (<50% of normal airflow) during sleep, which lasts at least 10 seconds; not an apnea.

insomnia Difficulty initiating or maintaining sleep.

IPPB abbr. intermittent positive pressure breathing

MSLT abbr. multiple sleep latency test

NREM abbr. non-rapid eye movement sleep

OSA abbr. obstructive sleep apnea

OSAS abbr. obstructive sleep apnea syndrome

parasomnia An episodic disorder of arousal, partial arousal, or sleep stage transition that manifests as abnormal movement or behavior during sleep, such as sleepwalking, sleep terrors, and REM sleep behavior, not a dyssomnia.

PLMS abbr. periodic limb movements during sleep

PPP abbr. palatopharyngoplasty

PSG abbr. polysomnography

RDI abbr. respiratory disturbance index; synonymous with AHI

REM abbr. rapid eye movement

RERA abbr. respiratory effort-related arousals, a new designation for UARS

RLS abbr. restless legs syndrome

SDB abbr. sleep disordered breathing

SEM abbr. slow eye movement

sleep Physiologic process characterized by a reduction of alertness associated with specific brain activity and eye movement patterns.

sleep disordered breathing An inclusive term that describes all respiratory abnormalities during sleep.

snoring A noise produced primarily with inspiration during sleep caused by the vibration of the soft palate and the pillars of the oropharyngeal inlet. All snorers have incomplete obstruction of the upper airway

somnolence Difficulty maintaining alert wakefulness so that a person falls asleep if not actively kept aroused.

UAR abbr. upper airway resistance

UARS abbr. upper airway resistance syndrome

UP3 abbr. uvulopalatopharyngoplasty; also UPPP