Dictionary: Sleep Apnea and CPAP Terms

A

Aerophagia: Swallowing of excess air, which can cause bloating, gas, and abdominal discomfort, sometimes as a side effect of CPAP therapy.
AHI (apnea-hypopnea index): AHI is a scale that tells whether you have a sleep disorder called sleep apnea and, if so, how serious it is. AHI represents the number of apneas and hypopneas per hour of sleep.
APAP (auto-titrating positive airway pressure): PAP device that adjusts automatically in response to changes in a user’s breathing patterns. Used in the treatment of sleep apnea.
Apnea: Repetitive episodes of complete or partial upper airway blockage during sleep. During an apneic episode, the diaphragm and chest muscles work harder as the pressure increases to open the airway. A person can stop breathing for as long as 20 seconds or more. Breathing usually resumes with a loud gasp or body jerk.

B

BiPAP or BPAP (bi-level positive airway pressure): PAP device that delivers air into airways at two different air pressure settings: one for inhalation and another for exhalation.

C

Cataplexy: Symptom of narcolepsy; consists of a sudden loss of muscle tone that leads to feelings of weakness and a loss of voluntary muscle control.
CBT-I: Cognitive behavioral therapy treatment specific to insomnia. In some cases, this therapy includes interventions that are meant to help people identify and correct inappropriate thoughts and beliefs that may contribute to their sleep problems.
Central sleep apnea (CSA): Sleep disorder in which the brain fails to signal the muscles to breathe.
Cheyne-Stokes respirations: Pattern of breathing marked by cycles of increasing and decreasing breaths followed by pauses in breathing.
Chronotherapy: A behavioral technique in which bedtime is gradually adjusted; used in cases when the patient’s sleep-wake pattern is out of synch with the external environment.
Circadian rhythm: Biological rhythm that includes the internal clock, which influences when, how much, and how well people sleep.
Comorbidities: The presence of one or more additional medical conditions often co-occurring with a primary condition.
Compliance: How consistently a person uses their prescribed CPAP therapy, often measured by hours of use per night.
CPAP (continuous positive airway pressure): A PAP device that delivers air into airways through a mask at a consistent, continuous pressure.

D

Dental appliance: Oral appliance designed to treat obstructive sleep apnea (OSA), primary snoring, and associated symptoms.
Diabetes, type 2: Disease in which the body’s ability to produce or respond to the hormone insulin is impaired, resulting in abnormal metabolism of carbohydrates and elevated levels of glucose in the blood and urine. Often seen in sleep apnea patients.
Drug-induced sleep endoscopy (DISE): Procedure in which a small camera is used to examine the airway while a person is sedated to identify areas of obstruction during sleep.
Durable medical equipment provider (DME): Business that sells healthcare-related items intended for use in the home for an extended period. With a doctor’s prescription, DMEs provide and service sleep apnea equipment, such as CPAP machines, hoses, filters, and masks.

E

EASE (endoscopically-assisted surgical expansion): Operation for obstructive sleep apnea (OSA) that widens the upper and lower jaws to expand the nasal area and the palate and stiffen the soft palate, thus creating more space. Based on the findings that patients with OSA often have narrow jaws, which result in constricted nasal airways and back of the tongue shift resulting in airway obstruction.
ENT: See Otolaryngologist.
EPAP (expiratory positive airway pressure): Treatment that creates resistance during exhalation to help keep the airway open without using a powered machine.
EPR (expiratory pressure relief): CPAP feature that lowers air pressure during exhalation to make breathing feel more comfortable.

F

Full-face mask: Type of CPAP mask that provides a secure seal around the patient’s mouth and nose, giving users flexibility to breathe through either their nose or mouth. Considered an ideal choice for mouth breathers or people who experience frequent allergies or nasal congestion.

G

General practitioner: A doctor who treats acute and chronic illnesses and provides preventive care and health education to patients. Often a PHP.
GERD (gastroesophageal reflux disease): Sometimes called reflux. A chronic disease that occurs when stomach acid or bile flows into the food pipe and irritates the lining. Often seen in sleep apnea patients.
GP: See General Practitioner.

H

Heart disease: Any disorder that affects the heart. Often seen in sleep apnea patients. Types of heart disease include: arrhythmia (abnormal heart rhythm), atherosclerosis (hardening of the arteries), cardiomyopathy (heart’s muscles harden or grow weak), congenital heart defects, coronary artery disease, and heart attacks.
Home sleep test (HST): Portable monitoring device used to diagnose sleep apnea by tracking breathing, oxygen levels, and other key metrics while a person sleeps at home.
Hose: Cylindrical, hollow plastic tubing that connects the CPAP machine to the CPAP mask. Air is compressed in the CPAP machine and then delivered through the hose to the mask. There are two main types of hoses: standard and heated.
Humidifier: CPAP component that adds moisture to the air to reduce dryness in the nose, mouth, and throat.
Hypopnea: Shallow breathing but not a complete pause in breathing (apnea). Hypopneas and apneas cause sleep interruption, a decrease in oxygen levels, and in general cause an individual to feel excessive daytime sleepiness.

I

Insomnia: Difficulty initiating and/or staying asleep. Often seen in sleep apnea patients.
Inspire therapy (hypoglossal nerve stimulation): Implanted device that stimulates the tongue muscles during sleep to help keep the airway open.
Interdisciplinary healthcare: Approach to healthcare that involves team members from different medical disciplines working together with a common purpose. In the case of sleep apnea, a patient might have been diagnosed by a family doctor, then sent to a pulmonologist, neurologist, or sleep specialist for treatment.
Internist: Doctor who treats adults with diseases and conditions that affect the internal organs. Often a PHP.

L

Leak rate: Measurement of how much air escapes from a CPAP mask, typically expressed in liters per minute (L/min).

M

Micrognathia: Condition in which the lower jaw is smaller than normal, which can affect airway size and increase the risk of sleep apnea.
Mixed sleep apnea: Combination of central sleep apnea and obstructive sleep apnea.
Mouth breathing: Habit of breathing through the mouth instead of the nose, which can contribute to snoring and CPAP mask leaks.
Multiple sleep latency test (MSLT): Test that assesses the severity of sleepiness by measuring the speed of falling asleep performed in a series of naps that follows a full night of polysomnography in a sleep laboratory. MSLT is an essential tool used to diagnose narcolepsy.

N

Narcolepsy: Neurological condition in which a person has a hard time staying awake during the day. A person with narcolepsy may suddenly fall asleep during an activity.
Nasal mask: CPAP mask that covers a person’s nose from the bridge to their upper lip area to deliver indirect airflow to the airway.
Nasal pillow mask: CPAP mask that uses two soft and pliable silicone “pillows” that are inserted into the nostrils.
Neurologist: Doctor with in-depth training in nervous systems and brain disorders, including central sleep apnea, insomnia, and restless leg syndrome.
Nocturnia: Frequent nighttime urination. Often seen in sleep apnea patients.
Non-24-hour sleep-wake disorder: Circadian rhythm disorder in which the sleep-wake pattern does not conform to the usual 24-hour cycle.
Non-rapid eye movement (NREM) sleep: One of the two basic states of sleep; consists of stages 1, 2 (light sleep), and 3 (deep sleep). No rapid eye movement exists in these stages.

O

Obstructive sleep apnea (OSA): Most common kind of sleep apnea, caused by a blockage of the upper airway that causes the body to struggle to get air.
Oral appliance: Custom-fitted device worn in the mouth during sleep to reposition the jaw or tongue and help keep the airway open.
Otolaryngologist: Ear, nose, and throat doctor.
Oxygen desaturation index (ODI): Measure of how often blood oxygen levels drop during sleep, usually expressed as the number of drops per hour.

P

PAP (positive airway pressure) therapy: Treatment that uses pressurized air delivered through a mask to keep the airway open during sleep.
Parasomnias: Abnormal behaviors during sleep that interrupt sleep and can result in injury, insomnia, and/or excessive daytime sleepiness
Periodic limb movement disorder (PLMD): Disorder in which rhythmic jerking of the legs interrupts sleep, causing insomnia and/or excessive daytime sleepiness.
PHP: Primary Healthcare Provider.
Polysomnography: Test that records aspects of sleep and a variety of body functions during sleep, including brain activity, breathing patterns, heart rhythms, and limb movements.
Positional therapy: Changing sleep position, such as avoiding back sleeping, to reduce airway obstruction and improve breathing.
Pulmonologist: Doctor who specializes in the respiratory system from the windpipe to the lungs.

R

Ramp time: CPAP feature that starts therapy at a lower pressure and gradually increases to the prescribed level to help users fall asleep more comfortably.

S

Sleep apnea: Sleep disorder that occurs when a person’s breathing temporarily stops during sleep.
Sleep hygiene: Practices, habits, and environmental factors that are important for getting sound sleep.
Sleep lab: An office or clinic that is set up for overnight stays, usually in a hospital or sleep center. Labs are staffed by sleep technologists who administer sleep tests.
Sleep paralysis: Symptom of narcolepsy; involves the temporary inability to move or speak while falling asleep or waking up. May also be caused by sleep deprivation, irregular sleep patterns, family history, and other causes.
Sleep study: See Polysomnography.
Sleep technologist: Trained and certified healthcare professional who assists in the clinical assessment, monitoring and testing, diagnosis, management, and prevention of sleep-related disorders.
Snoring: Sound caused by vibration of tissues in the airway during sleep, often due to partial airway obstruction.
Surgery: Several types of operations exist to change the head, mouth, nose, face, jaw, chin, nose, and throat to treat sleep apnea.

T

Titration study: Sleep study used to determine the optimal CPAP pressure needed to keep the airway open.

U

Upper airway resistance syndrome (UARS): Sleep disorder in which increased resistance in the airway disrupts breathing and sleep without full apneas.
UPPP (uvulopalatopharyngoplasty): Surgical removal of soft tissue at the back of the throat that can include all or part of the uvula (soft tissue flap that hangs down at the back of the mouth), parts of the soft palate and tissue at the sides of the throat, and tonsils and adenoids.

V

Ventilator: Medical device that helps support or control breathing, typically used in more serious or critical conditions.