Sleep Terminology Glossary

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Learn more about some sleep-related terms right here; you’ll practically be a sleep authority yourself in no time.

  • 5-HTP / L-5-hydroxytryptophan: An amino acid necessary for producing the neurotransmitter serotonin. Sometimes sold as an OTC sleep aid.
  • Acetaminophen / Paracetamol / Tylenol: A common painkiller and fever reducer.
  • Actigraphy: A method of tracking sleep habits that involves a patient wearing a device on the wrist to record data.
  • Active Ingredient: The ingredient inside a supplement that causes change in the human body.
  • Alkaline Earth Metal: Found on the second column of the periodic table of the elements. These elements are somewhat reactive and can be found in nature in some form. Magnesium is an alkaline earth metal.
  • Alternate Nostril Technique / Nadi Shodhana: A pranayama, or yogic breathing technique, that involves inhaling through the left nostril and exhaling through the right nostril.
  • American Academy of Sleep Medicine (AASM): A professional medical society that has dedicated itself to promoting better health through optimizing sleep since 1975.
  • American Society of Clinical Hypnosis (ASCH): An organization that provides training for healthcare professionals to attain clinical hypnosis certification.
  • Amino Acid: An organic compound that is notably involved in the processes of protein production, tissue repair, and nutrient absorption.
  • Amygdala: A region of the brain’s limbic system; the amygdala is associated with processing emotions and emotionally strong memories.
  • Antihistamine: A drug class that blocks the release of histamine. It may help with allergies, cold or flu symptoms, and other conditions.
  • Attention Deficit Hyperactive Disorder (ADHD): A common condition characterized by symptoms like difficulty focusing and issues with self-control. Research suggests there is a link between ADHD and sleep issues.
  • Auto Sensory Meridian Response / ASMR: A relaxed sensation usually accompanied by tingles. It seems to be triggered by audio-visual stimuli.
  • BedJet: A fan specially designed for beds to help people achieve a cooler sleeping environment.
  • Binaural: Relating to the use of both ears.
  • Body Scanning: A type of meditation that involves mentally “scanning” the body and focusing on how each part feels.
  • Brown Noise / Brownian Noise / Red Noise: Random noises with alternating frequencies and energies, with higher frequencies having lower energy and low frequencies having high energy. It is named after Robert Brown, who discovered Brownian motion, which is similar to Brown noise; these sounds may help people sleep better.
  • Cannabidoil (CBD): A substance derived from cannabis; pure CBD does not contain THC. Sometimes sold as an OTC health supplement, and its legality is in dispute in many areas.
  • Cardiac Coherence: A systematic heart rate variability that specifically helps influence parts of the nervous system.
  • Cataplexy: A sudden loss in muscle tone or a feeling of muscle weakness that is usually triggered by strong emotional expressions, including laughter, stress and fear.
  • Certification in Clinical Hypnosis (CCH): A clinical certification that healthcare professionals can obtain to improve their effectiveness in using hypnotherapy as a treatment method; usually involves training and independent practice.
  • CertiPUR-US: A certification overseen by the not-for-profit Alliance for Flexible Polyurethane Foam, Inc., that applies to foams. Foams with this certification are tested for harmful substances like lead, mercury, and formaldehyde.
  • Chamomile: A flower long used in herbal remedies, such as tea. Most chamomile tea is made of German or Roman varieties of this plant. Often used as a sleep aid, pregnant individuals should avoid Roman chamomile, as it may cause miscarriages.
  • Circadian Rhythm: The 24-hour sleep-wake cycle innate to living organisms; also referred to as the sleep-wake cycle.
  • Circadian Rhythm Sleep-Wake Disorder (CRSWD): A category of sleep disorders marked by the disconnection between your body’s circadian rhythm and the light-dark cycle, resulting in poor sleep.
  • Closed-Loop Production System: A sustainable manufacturing processes that reuses as much water and other materials as possible to reduce waste.
  • Cognitive Behavioral Therapy (CBT): A structured form of talk therapy that uses coping techniques to reframe harmful cognitive beliefs and behaviors.
  • Cognitive Behavioral Therapy for Insomnia (CBT-I or CBT-i): CBT focused specifically on helping people achieve higher quality rest.
  • Comorbidity: Having at least two medical conditions at the same time.
  • Cortisol: A hormone that is normally secreted by the human body. Individuals with anxiety and depression may experience a release of extra cortisol, which can lead to unpleasant side effects like disrupted sleep cycles. Those with insomnia tend to show elevated levels of this hormone.
  • Egyptian Cotton (EC): Cotton grown in Egypt from the Gossypium barbadense species, which has long and soft fibers. Genuine Egyptian cotton is extra-long staple.
  • Extra-Long Staple (ELS) Fibers: Fibers that are long and smooth, about 1 3/8” or 34 mm in length. Produce textiles that are unmatched in terms of softness and durability.
  • Deep Breathing / Diaphragm Breathing / Belly Breathing: A basic breathing technique that involves slow, deep breathing through the diaphragm.
  • Delayed Sleep-Wake Phase Disorder (DSWPD): Otherwise known as DSP, a Circadian Rhythm Sleep-Wake Disorder (CRSWD) characterized by a delayed sleep pattern and the inability to go to bed at a time that correlates with typical day-to-day activities and responsibilities.
  • Desyrel / Trazodone: Desyrel is the brand name of trazodone. Trazodone is an antidepressant many doctors prescribe off-label to patients with sleeping problems.
  • Dextromethorphan: A cough suppressant that may cause drowsiness.
  • Diaphragm: A section of the body that affects breathing and effectively separates the chest from the rest of the abdomen.
  • Dodow: A sleep aid that coaches people through relaxing breathing exercises.
  • Double Exhalation / 2-to-1 Technique: A breathing technique where one exhales twice as long as they inhale.
  • Doxylamine: A popular antihistamine used in the short-term treatment of insomnia.
  • Flannel: A material woven and brushed in a special way from any number of carded yarn fibers. Known for being warm and cozy, flannel is not synonymous with plaid.
  • Flat Head Syndrome / Plagiocephaly: A condition where a baby develops a flat spot on the back or side of the head; may be caused by regularly resting in one position.
  • Flavonoids: Organic compounds that may have beneficial properties for humans.
  • GABA / Gamma-Aminobutyric Acid: An inhibitory neurotransmitter that calms brain activity. Often sold as an OTC sleep aid.
  • Galvanic Skin Response (GSR): An emotionally triggered physiological response relating to the skin and sweat glands.
  • Gel-Infused Memory Foam: A special type of memory foam that is infused with gel in order to make it cooler to rest on.
  • Generally Recognized As Safe (GRAS): A label the U.S. Food & Drug Administration gives to items that research suggests is generally safe for human use.
  • Ginger: A plant that belongs to the same family as turmeric, and it is a popular staple in both herbal remedies and a variety of dishes and beverages. In herbal medicine, it is popular in treatments for anxiety, depression, and sleep issues.
  • Global Organic Textile Standard (GOTS): A certification that lists criteria for product safety, ethical labor practices, and sustainable manufacturing.
  • Glycine: An amino acid/inhibitory neurotransmitter that’s incredibly important in the production of proteins. Often sold in OTC sleep aids.
  • Grams Per Square Meter (GSM): Weight of a square meter of a given textile; an alternative measurement to thread count.
  • Heart Rate Variability (HRV): Variation between heartbeat intervals.
  • Histamine: A compound that plays a role in the body’s immune response.
  • Hippocampus: Another part of the brain’s limbic system; it is notably associated with memory.
  • Hops: Flowers from the Humulus luplus plant, a member of the hemp family. Often used in herbal remedies.
  • Humming Bee Breath / Bhramari Pranayama: A special yogic breathing technique that incorporates controlled vibrations. Produces a humming sound similar to that of a buzzing bee.
  • Hypersomnia: A condition characterized by excessive sleep and/or daytime sleepiness.
  • Hypnosis: A state of mind similar to sleep or unconsciousness.
  • Hypnotherapy: A treatment sought out to treat chronic pain, anxiety, PTSD and/or phobia(s).
  • Hypnotist: A person who conducts hypnotherapy. There are street hypnotists and certified hypnotists. The latter typically practices treatment in a clinical setting.
  • Hypocretin: A brain hormone responsible for regulating REM sleep and promoting wakefulness.
  • Inhibitory Neurotransmitter: A neurotransmitter that prevents certain neurons from firing.
  • Insomnia: A sleep disorder characterized by the difficulty of falling or staying asleep; can either be acute (short-term) or chronic (long-term).
  • Jet Lag: A temporary Circadian Rhythm Sleep-Wake Disorder (CRSWD) that often occurs when a person travels over multiple time zones in a short period of time; symptoms align with tiredness, anxiety and/or depression, and insomnia.
  • Lavender: A group of flowers in the mint family. English lavender (Lavandula angustifolia) is the most common source of lavender oil, which is often used in alternative medicine practices like aromatherapy.
  • Lemon Balm: The common name for Melissa officinalis, a plant in the mint family; often used in herbal remedies.
  • Linen: Lightweight and durable fabric made from flax. Often much more sustainable to produce than cotton or polyester.
  • L-Theanine L-γ-Glutamylethylamide: Theanine is an amino acid found in places like certain kinds of tea and mushrooms; the human body does not produce theanine. Often sold as an OTC sleep aid.
  • Lyocell: A special type of rayon. Manufacturers use a special spinning process to dissolve plant-based pulp, which creates fibers that can then be woven into textiles.
  • Magnesium: An alkaline earth metal. As a mineral, it is important for certain human biological functions. Having a magnesium deficiency may cause side effects like drowsiness and fatigue. Magnesium is often sold as an OTC sleep aid.
  • Major Depressive Disorder (MDD): A serious mental illness characterized by extremely low mood and a host of other symptoms like sleep disturbances. MDD places someone at a higher risk of suicide than the general population.
  • Melatonin: A natural hormone produced in the body’s pineal gland that regulates your sleep-wake cycle; a common supplement used to treat sleep disorders or problems.
  • Mindfulness: A state of being aware of the present; a technique used in many mental health practices that involves being in the present moment and accepting what is.
  • Misophonia: The intense dislike or hatred of certain sounds.
  • Multiple Sleep latency Test (MSLT): a test used in diagnosing sleep disorders that measures how long it takes a person to fall asleep and whether or not they experience REM sleep.
  • N1: First state of SWS where we begin falling asleep.
  • N2: Second state of SWS where we enter a light sleep.
  • N3: Also known as deep sleep, this is the third state of SWS.
  • Narcolepsy: A sleep disorder that results in daytime tiredness and sudden bouts of falling asleep; symptoms include insomnia, hallucinations and cataplexy.
  • Narcolepsy Type 1: A type of narcolepsy that displays cataplexy.
  • Narcolepsy Type 2: A type of narcolepsy that does not display cataplexy.
  • Neurotransmitters: Chemicals that help send signals across the brain.
  • Norepinephrine: A hormone and neurotransmitter that plays a part in body mobilization. Notably, its levels decrease with sleep and rise with wakefulness and stress.
  • Obstructive Sleep Apnea (OSA): A condition where someone will stop and then resume breathing multiple times as they rest; the most common form of sleep apnea.
  • Organization for Economic Co-operation and Development (OECD): An international economic organization.
  • Over-the-Counter (OTC) Supplements: Medications that do not require a prescription for purchase.
  • Parasomnia: A condition where unconscious individuals perform activities they would normally only do when awake. These activities include doing household chores, performing sex acts, and driving. Severe parasomnia can be extremely dangerous for both the afflicted individual as well as others.
  • Percale: A basic type of weave with a medium weight. Tight, crisp, and easily washable with a thread count that starts around 200.
  • Pima Cotton: Extra-long staple cotton grown from the Gossypium barbadense species of the plant.
  • Pink Noise: A random collection of sound waves where each octave has the same amount of energy; commonly found in nature, pink noise may help people sleep.
  • Ply: The number of threads a manufacturer twists together in a textile. Textiles can be either single ply or multi-ply.
  • Polysomnography (PSG): The gold standard method of tracking sleep habits and brainwave patterns, which may help physicians identify health problems in patients.
  • Pranayama: Ancient yogic practices that involve controlled, mindful breathing.
  • Primary Insomnia: Sleeplessness not caused by factors like major depression disorder or chronic pain.
  • Purple Passionflower / Maypop: Common name for Passiflora incarnata, a flowering vine often used in herbal remedies for its purported sedative qualities.
  • Rapid-Eye Movement Sleep (REM): This part of the sleep cycle is the stage where we most frequently dream.
  • Rayon: A plant-derived fiber; fabrics made from viscose.
  • Relaxing Breath / 4-7-8 Method: A calming breathing technique that involves inhaling for 4 seconds, holding the breath for 7 seconds, and exhaling for 8 seconds.
  • Respiratory Rate: How many breaths someone takes a minute. The average adult respiratory rate is 12-20 breaths per minute.
  • Reuptake Inhibitors: Drugs like SSRIs (selective serotonin reuptake inhibitors) or SNRIs (serotonin-nonrepinephrine reuptake inhibitor) that inhibit the reuptake, or reabsorption, of certain neurotransmitters.
  • Selective Serotonin Reuptake Inhibitor (SSRI): A class of antidepressants that inhibits the reabsorption of serotonin in the brain.
  • Serotonin: An important neurotransmitter that serves several important functions, including improving mood and regulating the sleep cycle.
  • Serotonin-Norepinephrine Reuptake Inhibitor (SNRI): Antidepressants that inhibit the reabsorption of serotonin and norepinephrine.
  • Serotonin Antagonist Reuptake Inhibitor (SARI): A class of drugs that block neurons from reabsorbing serotonin.
  • Secondary Insomnia: Sleeplessness that’s a symptom of another condition, such as a mental illness.
  • Shift Work Disorder (SWD): Otherwise known as Shift Work Sleep Disorder (SWSD), a Circadian Rhythm Sleep-Wake Disorder characterized by the disruption of the normal sleep cycle due to work hours outside of typical time frames.
  • Sinkage: How much “give” a mattress has when pressed.
  • Skullcap: Common name for the flowering genus Scuttellaria, which is part of the mint family. Skullcap notably contains lots of flavonoids, and many used it in herbal sleep remedies. 
  • Sleep Cycle: A period of alternating stages of REM and deep sleep. For adults, cycles last about 90 minutes, and there will be roughly 4-5 cycles a night. A single cycle is comprised of SWS, REM, and brief periods of awakening.
  • Sleep Deprivation: Not getting enough sleep or enough quality sleep; linked to serious health concerns such as stroke and diabetes.
  • Sleep Hygiene: Another term for sleep-related habits.
  • Sleep Latency / Sleep Onset Latency: How long it takes to fall asleep.
  • Sleep Onset Insomnia (SOI): A condition where someone specifically has difficulty with falling asleep.
  • Sleep Tracker Bullet Journal: An analog method of logging hours of sleep in a notebook with the goal of identifying themes and making sleep an intentional focus.
  • Slow-Wave Sleep (SWS) / Non-REM (NREM) Sleep: Colloquially known as deep sleep, slow wave sleep is comprised of 3 stages (N1, N2, N3). This period is marked by physical changes like slower brain waves and slightly lower body temperature.
  • Sleepytime®️ Tea:  A line of caffeine-free herbal teas from Celestial Seasonings.
  • Society for Clinical and Experimental Hypnosis (SCEH): An international organization of healthcare professionals who apply clinical hypnosis in their professions.
  • Sound Masking: When one sound seemingly covers up another sound; the premise behind white noise machines.
  • Spielman Model: A widely accepted model for explaining chronic insomnia; predisposing factors(s), precipitating trigger(s), and perpetuating habit(s) are the three pillars of this model.
  • Standard 100 by OEKO-TEX: Gold standard label for textile safety.
  • Sudden Infant Death Syndrome (SIDS): Refers to the loss of an infant under the age of 1 year that has no explainable cause. Back sleeping is the position associated with the lowest risk of SIDS.
  • Supima: A non-profit that licenses facilities, manufacturers, and retailers to use their trademark for American-grown Pima cotton.
  • Tart Cherry Juice: A juice made from tart cherries, which is often used as an OTC sleep aid.
  • Tencel: A brand name of lyocell fabric. Made from plant-based sources, usually eucalyptus, in a sustainable fashion. The fabric is well-known for its superior quality.
  • Tetrahydrocannabinol (THC): The compound in cannabis that gives people a “high.”
  • Thread Count (TC): How many threads are in an inch of a textile.
  • Unipolar Depression: Condition that features symptoms of clinical depression like severely low mood. Unipolar depression is distinct from bipolar depression, which is notable for alternating periods of mania.
  • USDA Organic: A certification set by the U.S. Department of Agriculture to determine if a product can be labelled “organic.”
  • Valerian: Valeriana officinalis is a flowering plant that has long been used in herbal medicine. It is still popular in OTC sleep remedies.
  • Vicks NyQuil™: A well-known commercial medicine that is designed to improve sleep quality during bouts of the cold or flu.
  • Viscose: A type of plant-derived fiber used to make rayon fabrics. Treating cellulose from plants with a certain solution creates viscose.
  • Vistaril / Hydroxyzine: Vistaril is the brand name of hydroxyzine. It is an antihistamine that is used to treat anxiety, allergies and, quite frequently, problems associated with sleep. Vistaril can also be used as anesthesia for surgery.
  • Visualization: A meditative technique that requires imagining a place, time, or memory that brings happiness; the goal is to use heavy sensory imagination and description to induce calmness.
  • White Noise: While often used interchangeably with background noise, white noise is also a technical term for a collection of various sound waves with the same intensity; often used as a relaxing background noise.
  • Zolpidem: A sedative often prescribed to treat insomnia.