Glossary

Plain English explanations of the words and terms used across Uma.

A

Access to Work (AtW)
Access to Work (AtW) is a UK government grant scheme that helps disabled people access the support they need to thrive at work.
Adaptogens
Adaptogens are natural ingredients, typically plants, herbs or mushrooms, which help your body build resilience to the physiological impact of chronic stress.
Adenomyosis
A condition in which the uterine lining grows into the muscle of the uterus, causing heavy and painful periods.
Adenosine
A molecule that builds up in the brain during wakefulness and promotes sleep pressure. Caffeine works by blocking adenosine receptors.
ADHD
ADHD is a lifelong neurodevelopmental and neurological difference that affects self-regulation and executive functioning.
Adrenaline
The hormone that raises your heart rate and blood pressure in response to stress.
Adult Disability Payment (ADP)
The Scottish version of PIP. In Scotland, you apply for ADP instead of PIP.
AFAB (assigned female at birth)
Assigned female at birth. Used when talking about hormonal biology that applies regardless of gender identity.
ALCAR (acetyl-L-carnitine)
A form of carnitine that crosses the blood-brain barrier and supports brain energy and BDNF production.
Alexisomia
A reduced ability to identify and label bodily sensations, such as hunger, thirst, pain, or the need to go to the toilet.
Alexithymia
Difficulty identifying and describing your own emotions.
Allistic
Not autistic.
Allopregnanolone
A calming brain chemical produced from progesterone. It activates GABA receptors and supports nervous system stability in the second half of the cycle.
Alpha brainwaves
A type of brain activity associated with calm, relaxed alertness. Increased by music, mindfulness, and rest.
AMH (anti-Mullerian hormone)
A hormone that reflects ovarian reserve. Used in fertility testing.
Amygdala
The brain's threat detection centre. Responsible for the fear and stress response.
Anovulation
A cycle in which ovulation does not occur. Linked to chronic stress, PCOS, and hormonal disruption.
Antidepressants
Medications prescribed for depression and, sometimes, anxiety.
Antioxidant
A substance that protects your cells from damage.
ATP (adenosine triphosphate)
The molecule that stores and transfers energy in cells. CoQ10 is essential for ATP production.
AuDHD
AuDHD is a term used by the neurodivergent community to describe a person who is both autistic and has ADHD. Rather than being a separate, official diagnosis, it highlights that the two neurotypes exist in one person and can overlap.
Auditory processing difficulties (APD)
Difficulty making sense of what you hear, especially in noisy places, even when your hearing is fine.
Autism
Autism is a lifelong neurological and neurodevelopmental difference that affects how a person processes the world, particularly in social and sensory contexts.
Autoimmune
When the immune system mistakenly attacks the body's own tissues.
Avoidance
Keeping away from thoughts, feelings, people, places or activities that remind you of a traumatic event.

B

Bacterial vaginosis
A common imbalance of bacteria in the vagina that can cause unusual discharge.
BDNF (brain-derived neurotrophic factor)
A protein that supports the growth, maintenance, and survival of neurons. Sometimes called brain fertiliser. Exercise, cold exposure, and some supplements increase BDNF.
Beta brainwaves
The brain activity pattern associated with active thinking and alertness.
BFRBs (body-focused repetitive behaviours)
Repetitive behaviours focused on the body, such as skin picking and hair pulling.
Bioavailability
The proportion of a substance that actually reaches the bloodstream and can be used by the body.
Bipolar
A mental health condition that causes extreme shifts in mood, energy and activity.
Blood sugar
The level of glucose in the blood.
Blood-brain barrier
The protective filter between the bloodstream and the brain that controls what gets in.
Blue light
Light from the sun and from screens that tells your brain it is daytime. At night it can delay sleep.
Body dysmorphia
Spending a lot of time worrying about flaws in your appearance that others often cannot see.
BPD (borderline)
Borderline personality (BPD) is a mental health condition that causes difficulties in regulating emotions and challenges in how you relate to yourself and others.
Burnout
Burnout is caused by chronic unmanaged stress.

C

Camouflaging
Another word for masking.
Carotenoids
Plant pigments with antioxidant properties. Found in orange, yellow, and red foods.
CBD (cannabidiol)
A compound from the hemp plant that does not make you high. It is used for calm, sleep and pain.
Central sensitivity syndromes
A group of conditions linked by chronic pain, inflammation, and nervous system hypersensitivity. Includes fibromyalgia, IBS, migraine, and chronic fatigue.
Choline
A nutrient essential for memory and brain function. One of the most under-consumed nutrients in women.
Circadian rhythm
The body's internal 24-hour clock that regulates sleep, hormones, mood, and metabolism.
Clinical threshold
The level at which a trait or symptom counts towards a diagnosis. Uma counts it at high levels, 61% or more.
Co-occurring
Happening alongside. A co-occurring condition is one you have as well as another.
Comorbidity
The condition of having two or more diseases at the same time.
CoQ10 (coenzyme Q10)
A nutrient essential for cellular energy production. Levels decline with age.
Corpus luteum
The structure left behind in the ovary after ovulation. It produces progesterone.
Cortisol
The body’s main stress hormone.
CPTSD (complex post-traumatic stress disorder)
Complex PTSD (CPTSD) is a mental health condition that can develop from prolonged or repeated exposure to trauma from which there is little or no chance of escape, such as long-term domestic abuse, child abuse, or torture.
Cytokines
Chemical messengers produced by the immune system. Pro-inflammatory cytokines promote inflammation; anti-inflammatory cytokines reduce it.

D

Default mode network
The part of the brain that becomes active when your mind wanders, ruminates, or overthinks.
Demand avoidance
A strong, anxiety-driven urge to avoid everyday demands and expectations, even ones you want to do.
Dermatillomania
Repeated skin picking that is hard to stop. A body-focused repetitive behaviour.
DHEA
A hormone produced by the adrenal glands that is a precursor to oestrogen and testosterone.
DHEAS (dehydroepiandrosterone sulphate)
A hormone produced by the adrenal glands, measured in hormonal testing panels.
Disabled Students Allowance (DSA)
UK government help with the extra costs of studying with a disability.
Dissociation
Dissociation is a feeling of being disconnected from your body, surroundings, or sense of self.
Distress Brief Intervention (DBI)
A Scottish service offering quick, compassionate support to people in emotional distress, available through 111 or your GP.
Dopamine
The motivation, reward, and pleasure hormone.
Dopamine dysregulation
Disrupted dopamine signalling in the brain, affecting motivation, attention, and reward. Not a dopamine deficiency.
DSM-5
The American diagnostic manual clinicians use to diagnose ADHD and autism. The 5 means it is the fifth edition.
Dysarthria
Difficulty speaking clearly because the muscles used for speech are weak or hard to control.
Dysautonomia
A disorder of the autonomic nervous system, which controls automatic body functions such as heart rate, blood pressure and digestion.
Dysbiosis
An imbalance in the gut microbiome, where harmful bacteria outnumber beneficial ones.
Dyscalculia
A learning difference that affects understanding numbers and maths.
Dysgraphia
A learning difference that affects handwriting and putting thoughts into writing.
Dyslexia
A learning difference that affects reading and spelling.
Dysmenorrhoea
Painful periods.
Dyspareunia
Pain during or after sex.
Dyspepsia
Indigestion: discomfort or burning in the upper stomach.
Dyspraxia
A neurodevelopmental difference that affects movement, coordination and planning.

E

Echolalia
The repetition of words or phrases, either immediately or delayed. A common autistic communication pattern.
Echopraxia
The involuntary repetition or imitation of another person's movements.
EDS (Ehlers-Danlos syndrome)
A group of connective tissue conditions causing hypermobility, joint pain, and fragile skin. hEDS is the hypermobile subtype.
Emotional dysregulation
Emotional dysregulation describes difficulties managing your emotions.
Emotional flashback
Unlike a visual flashback where you see a memory, an emotional flashback is an intense feeling of being back in the trauma.
Endometriosis
A condition in which tissue similar to the uterine lining grows outside the uterus, causing chronic pain and inflammation.
Endorphins
The body’s natural painkillers, released through exercise, laughter, and touch.
Equality Act 2010
The UK law that protects disabled people from discrimination and requires employers, landlords and service providers to make reasonable adjustments.
Estrobolome
The part of the gut microbiome responsible for metabolising and regulating oestrogen levels.
Executive functions
The brain’s management system, focus, organisation, memory, impulse control, and emotional regulation.
Externalised hyperactivity
Externalised hyperactivity is where physical and verbal restlessness are outwardly visible.

F

Fawning
A response to threat where you try to please or appease others to stay safe.
Fenugreek
A phytoestrogen with evidence for supporting hormonal balance and blood sugar regulation.
Fibromyalgia
A chronic condition characterised by widespread muscle pain, fatigue, and heightened sensitivity to pain. More common in women and linked to central sensitisation.
Flavonoids
Plant compounds with anti-inflammatory and antioxidant properties.
Flow
A state of deep, enjoyable concentration where time seems to disappear. Hyperfocus is closely related.
Follicular phase
The first half of the menstrual cycle, from menstruation to ovulation.
FSH (follicle-stimulating hormone)
A hormone that triggers egg development. Rises in perimenopause.

G

GABA (gamma-aminobutyric acid)
The body’s main calming neurotransmitter.
Gastroparesis
When the stomach empties more slowly than it should, causing fullness, nausea or bloating.
Global developmental delay
When a young child reaches several developmental milestones, such as walking and talking, later than expected.
Glutamate
The body’s main excitatory neurotransmitter.
Glutathione
The brain's master antioxidant.
Gut microbiome
The trillions of bacteria, fungi, and other microorganisms living in your digestive tract that affect mood, immunity, and hormone balance.
Gut-brain axis
The two-way communication network between the gut and the brain, using nerve signals, hormones, and the immune system.

H

Heart rate variability
The best available measure of how well your nervous system recovers from stress.
hEDS (hypermobile Ehlers-Danlos syndrome)
The most common type of Ehlers-Danlos syndrome, where joints move further than usual and connective tissue is fragile.
Heritable
Passed down in families through genes.
Histamine
A chemical released by mast cells that can cause allergy-like reactions.
HPA axis
The body's main stress response system, linking the brain and the adrenal glands.
HPG axis
The system that controls the production of sex hormones.
5-HTP (5-hydroxytryptophan)
A naturally occurring amino acid the body uses to make serotonin.
Hyperacusis
Sensitivity to everyday sounds that others find tolerable. Often co-occurs with tinnitus and misophonia.
Hyperarousal
Hyperarousal is the physiological side of hypervigilance, where your fight or flight system is stuck in the on position.
Hyperextensibility
Skin that stretches further than usual.
Hyperfocus
Hyperfocus is a state of deep concentration and complete absorption in a task or activity leading to a loss of self-consciousness and sense of time.
Hypergeusia
Heightened sensitivity to taste.
Hyperglycaemia
High blood sugar.
Hyperlexia
Early or advanced reading, writing and decoding skills. Hyperlexia is not a stand-alone diagnosis and is part of the autism spectrum.
Hypermentalising
Overthinking what other people are thinking or feeling, and reading more into it than is there.
Hypermobility
A greater than usual range of movement in the joints, and the most common feature of hEDS.
Hypermobility
Joints that move further than usual. It can come with joint pain, injuries and fatigue.
Hyperosmia
Heightened sensitivity to smell.
Hyperthermia
When the body gets too hot.
Hyperverbal
Talking a lot, quickly, or in great detail.
Hypervigilance
Hypervigilance is a state of constant alertness where you are always scanning your environment for threats.
Hypoglycaemia
Low blood sugar.

I

IBS (irritable bowel syndrome)
A common digestive condition causing cramping, bloating, and changes in bowel habits. Three times more common in women.
ICD-11
The World Health Organisation's international diagnostic manual. CPTSD was added to it in 2018.
IL-10 (interleukin-10)
The body's main anti-inflammatory agent. Higher IL-10 levels are linked to lower pain and better immune regulation.
Inflammation
The body's natural response to injury or infection. When it lasts a long time, it can contribute to pain, low mood and illness.
Inflammatory cytokines
Chemical messengers that drive inflammation and pain when the immune system is activated.
Informant
Typically a family member who knew you as a child, who a clinician may ask to talk to during an assessment.
Insulin
The hormone that moves sugar from your blood into your cells for energy.
Insulin resistance
When the body’s cells stop responding properly to insulin, leading to high blood sugar. Strongly linked to PCOS.
Intellectual disability
Intellectual ability that is significantly lower than average and in the bottom 2.5% of the population; ID often co-occurs with autism. Referred to as a general learning disability in the UK.
Intellectual giftedness
Intellectual ability that is significantly higher than average and in the top 2.5% of the population; IG often co-occurs with autism.
Internalised hyperactivity
Internalised hyperactivity can show up as constant mental chatter, excessive mind wandering, multiple thoughts at the same time, associative or creative thinking.
Interoception
The ability to read and understand signals from inside your own body.
Isoflavones
Plant compounds found in soy and red clover that can weakly mimic oestrogen in the body.

K

Kinetosis
Motion sickness.
KYNA (kynurenic acid)
An antioxidant and natural NMDA receptor blocker. Produced from tryptophan. Acts as the brain's emergency braking system for glutamate toxicity.
Kynurenine
A breakdown product of tryptophan. Under chronic stress and inflammation, more tryptophan is diverted to kynurenine rather than serotonin.
Kynurenine pathway
A stress-activated metabolic pathway that diverts tryptophan away from serotonin production.

L

Leukotrienes
Chemicals released by mast cells that can constrict breathing.
LH (luteinising hormone)
The hormone that triggers ovulation.
Lignans
Plant compounds found in flaxseed and other foods that can be converted by gut bacteria into weak oestrogens.
Limbic system
The brain's emotion, memory, and threat detection network.
Liposomal
A delivery format in which the active compound is encased in a fat layer to improve absorption. Liposomal supplements are generally better absorbed than standard capsules.
Long COVID
Symptoms that continue for weeks or months after a COVID-19 infection.
Luteal phase
The second half of the menstrual cycle, from ovulation to menstruation. Progesterone and allopregnanolone are highest in this phase.
Lutein and zeaxanthin
Antioxidants found in dark leafy greens that absorb blue light in the retina, protecting against light-induced migraine and eye fatigue.

M

Maca root
A phytoestrogen and adaptogen that supports hormonal balance and energy.
Magnesium
The brain's natural braking system.
Masking
The effort of hiding or suppressing your natural neurodivergent traits to fit in.
Mast cells
A type of immune cell; in MCAS they become overly reactive and release inflammatory chemicals.
Mast cells
Immune cells that release histamine and other chemicals during allergic reactions.
MCAS (mast cell activation syndrome)
A condition in which mast cells release too many inflammatory chemicals, causing widespread symptoms including flushing, fatigue, and digestive issues.
ME/CFS (myalgic encephalomyelitis / chronic fatigue syndrome)
A long-term condition with extreme tiredness that does not improve with rest and gets worse after activity.
Mechanoreceptors
Sensory receptors in the skin and muscles that respond to touch, pressure, and vibration.
Melatonin
The sleep hormone, produced from serotonin when it gets dark.
Meltdown
An intense, involuntary response to overwhelm, such as crying, shouting or a need to escape. It is not a choice or a tantrum.
Menopause
The point when periods have stopped for 12 months in a row.
Microbiome
The community of bacteria living in your gut that affects mood, immunity, and hormone balance.
Migraine with aura
A migraine that comes with warning signs such as flashing lights, zigzag lines or tingling before or during the headache.
Misophonia
An intense emotional or physical response to specific sounds, often chewing, breathing, or tapping.
Mitochondria
The energy-producing structures in cells. Sometimes called the cell's powerhouses. Relevant to chronic fatigue and CoQ10 supplementation.
Monotropism
A way of thinking where attention is pulled strongly towards a few interests at a time.
MS (multiple sclerosis)
A condition where the immune system damages the protective coating of nerves.
Myofascial pain
Pain arising from the muscles and their surrounding connective tissue, often presenting as trigger points.

N

Negative self-concept
Persistent beliefs that you are worthless or a failure, often with deep feelings of shame.
Neuroaffirmative
Language and approaches that respect neurodivergence as a natural difference rather than a problem to be corrected.
Neurodegeneration
The progressive loss of neurons and nervous system function.
Neurodivergent
Having a brain that works differently from what is considered typical, including ADHD and autism.
Neurodiverse
A group where one or more group members significantly differ in mental or neurological functions, from other members.
Neurodiversity
The range of differences in individual brain function as part of normal variation in the human population.
Neurodiversity paradigm
A framework for understanding mental and neurological differences and accepting people who would otherwise be pathologised as 'disordered' under the psychiatric model.
Neuroinclusion
Intentionally including and accommodating people who identify as neurodivergent.
Neuroinflammation
Inflammation occurring in the brain and nervous system.
Neurominority
Any group that differs in mental or neurological function from what is considered typical of most people.
Neuronormativity
Favouring neurotypical ways of being and rejecting divergent ways of thinking, feeling, or behaving.
Neuropathy
A loss of sensation and numbness.
Neuroplasticity
The brain's ability to form and reorganise connections in response to experience and learning.
Neuropride
A feeling of deep pleasure or satisfaction derived from celebrating one's unique neurodivergent strengths.
Neuroshame
A toxic negative emotion caused by a belief you are unworthy of support, connection, love or belonging because your brain is biologically different, society is intolerant of difference and you have internalised society's abuse, exclusion and rejection of you.
Neurotoxicity
Damage to nerve cells caused by a substance or process.
Neurotransmitter
A chemical messenger that carries signals between nerve cells, such as dopamine or serotonin.
Neurotrophic
Helping nerve cells grow, survive and connect.
Neurotypical (NT)
Not differing in mental or neurological function from what is considered typical of most people, though still part of the normal range in humans.
NMDA receptors
Receptors in the brain that respond to glutamate. Magnesium blocks these receptors to prevent excitotoxicity.
NMDA receptors
Receptors in the brain that respond to glutamate and are involved in learning and memory.
Non-binary
Having a gender identity that is not only woman or man.
Noradrenaline
A hormone and neurotransmitter that regulates attention, focus, and alertness.
Noxacusis
Pain triggered by sound. Distinct from hyperacusis, which involves discomfort rather than pain.

O

OAB (overactive bladder)
A sudden, frequent need to urinate that is hard to hold.
OCD (obsessive compulsive disorder)
A mental health condition where a person has unwanted, repeated thoughts and feels driven to repeat certain actions to ease the distress they cause.
Oestrogen
A sex hormone that regulates mood, brain function, and the menstrual cycle. Acts as a natural antidepressant by supporting serotonin and dopamine production.
Omega-3 fatty acids
Essential fats found in oily fish and some plants that reduce inflammation and support brain health.
Ovulation
When an ovary releases an egg, around the middle of the menstrual cycle.
Oxytocin
The bonding hormone, released through touch, connection, and trust.

P

Parasympathetic nervous system
The body's rest and digest system.
PCOS (polycystic ovary syndrome)
A hormonal condition characterised by high androgens, irregular periods, and insulin resistance. Disproportionately affects neurodivergent women.
Perimenopause
The years leading up to menopause, when oestrogen and progesterone levels rise and fall unpredictably.
Personal Independence Payment (PIP)
UK government help with the extra costs of living with a disability. No diagnosis needed, it is based on how things affect your daily life.
Phosphatidylserine
A fat found in brain cell membranes that supports memory, focus, and stress regulation.
Photophobia
Sensitivity to light.
Photosensitivity
Photosensitivity means light causes physical pain.
Phytoestrogens
Plant compounds that can interact with oestrogen receptors in the body. Found in soy, red clover, flaxseed, and other plants.
Piperine
The active compound in black pepper that slows the enzymes that break down certain supplements, improving their absorption. Found in turmeric and resveratrol formulas.
PMDD (premenstrual dysphoric disorder)
A severe form of PMS characterised by significant mood disruption in the luteal phase. Recognised in the DSM-5.
PME (premenstrual exacerbation)
The worsening of an existing condition in the luteal phase. Distinct from PMDD.
PMS (premenstrual syndrome)
Physical and emotional symptoms in the luteal phase, less severe than PMDD.
Positive psychology
The scientific study of how we can cultivate purpose and wellbeing and reach 'optimal human functioning' (or 'flourishing').
PoTS (postural tachycardia syndrome)
A condition in which heart rate increases abnormally on standing, causing dizziness, fatigue, and brain fog. More common in women and frequently co-occurs with hEDS and MCAS.
Prefrontal cortex
The front part of the brain responsible for executive functioning, decision-making, impulse control, and working memory.
Probiotics
Live bacteria that support gut health. Found naturally in fermented foods like yoghurt, kefir, sauerkraut, kimchi, and kombucha.
Progesterone
A sex hormone that calms the nervous system and supports sleep. Essential for GABA production.
Progesterone steal
When the body prioritises cortisol production under chronic stress, diverting the raw materials away from making progesterone, oestrogen, and testosterone.
Prolactin
A hormone produced by the pituitary gland. Chronically elevated prolactin suppresses ovulation and shortens the luteal phase.
Proprioception
The sense of your own body's position and movement in space.
Prostaglandins
Compounds produced during menstruation that cause cramping and inflammation.
Psychometric
Describes questionnaires and tests designed to measure how people think, feel and behave.
Psychosis
Losing touch with reality, for example seeing or hearing things others do not.
PTSD (post-traumatic stress disorder)
A mental health condition that can develop after a frightening or distressing event. It includes re-experiencing, avoidance and a constant sense of threat.
Pyridoxal-5-phosphate (P5P)
The active form of vitamin B6 that the body actually uses.

R

Re-experiencing
Reliving a traumatic event in the present, through intrusive memories, flashbacks or nightmares.
Reasonable adjustments
Changes an employer makes to remove disadvantages caused by a disability or chronic illness, such as flexible hours, equipment, software or coaching.
Reasonable adjustments
A reasonable adjustment is a change made to a job, study environment, or service that removes a disadvantage for a disabled person. This can include flexible working hours, a quiet workspace, or changes to communication methods.
Rejection sensitivity
Rejection sensitivity is an extreme emotional, physiological, or behavioural reaction to perceived or actual rejection, abandonment, criticism, blame, or exclusion.
Relational difficulties
Difficulty feeling close to other people and keeping relationships going.
REM sleep
Rapid eye movement sleep, the stage of sleep when most dreaming happens.
Resveratrol
A phytoestrogen found in red grapes and berries with antioxidant and oestrogen-modulating properties.
Rumination
Overthinking: repetitive thinking about the same worries or events.

S

SAD (seasonal affective disorder)
A form of depression linked to reduced light exposure in winter months. More common in women and in ADHD people.
Savant syndrome
Savant means 'learning' or 'scholar' in French. Savant syndrome is characterised by exceptional talents in one or more domains together with an eidetic memory. Savant syndrome is not a clinical diagnosis. Savant syndrome most commonly co-occurs with autism.
Schizophrenia
A mental health condition that can involve psychosis and changes in thinking and behaviour.
Self-identification
Recognising yourself as autistic or ADHD without a medical diagnosis. Autism and ADHD are identities, and many UK government services accept self-identification.
Sensory processing differences
Differences in how your brain takes in and responds to information from the senses. You may be more sensitive (hypersensitive) or less sensitive (hyposensitive).
Serotonin
The happy hormone, produced mainly in the gut.
SHBG (sex hormone-binding globulin)
A protein that carries sex hormones in the blood. Low SHBG increases the amount of active testosterone.
Shutdown
A quieter response to overwhelm where you withdraw, go silent or struggle to speak or move.
Sinusitis
Swelling of the sinuses, often after a cold, causing a blocked nose and facial pain.
Social model of disability
The social model of disability postulates that neurodivergent people are disabled by society's failure to appreciate their strengths or accommodate their differences.
Somatic symptoms
Somatic symptoms are physical sensations or bodily pains that are caused or made worse by emotional distress and trauma.
Somatosensory system
The part of your nervous system that senses touch, temperature, pain and body position.
Spiky profile
A mixture of significantly elevated abilities and increased difficulties relative to neurotypicals.
Stimming
Repetitive self-stimulatory behaviours (stimming) are repetitive movements or actions that help autistic people regulate their nervous system and emotions.
Stimulants
Stimulants are controlled medications for ADHD and can only be prescribed to people with a medical diagnosis.
Subject Access Request (SAR)
Anyone registered with a GP can request access to their medical records by making a Subject Access Request (SAR) to their GP.
Sunflower lanyard
The sunflower lanyard can help you disclose your disability without words. The sunflower shows staff you might need extra assistance while you travel, eat, or shop around the world.
Sympathetic nervous system
The body's fight or flight system.
Synaesthesia
A neurological experience in which one sense triggers another, for example seeing colours when hearing music, or tasting words.

T

tDCS (transcranial direct current stimulation)
A gentle, low electrical current passed through pads on the head to stimulate areas of the brain.
Testosterone
An androgen hormone present in small amounts in women and AFAB people. High testosterone in women is linked to PCOS, insulin resistance, and high blood sugar. The relationship between testosterone and libido in women at physiological levels is not well supported by evidence.
Theta brainwaves
The brain activity pattern associated with daydreaming and mind-wandering.
Theta waves
A type of brain activity associated with daydreaming and mind-wandering.
Tinnitus
A persistent ringing, buzzing, or humming sound in one or both ears with no external source. More common in people with hyperacusis and auditory processing difficulties.
TMJ (temporomandibular joint disorder)
A condition causing jaw pain, headaches, and facial tension. Three times more common in women.
Treatment-resistant depression (TRD)
Treatment-resistant depression (TRD) is depression that has not improved with two or more antidepressants.
Trichotillomania
Repeated hair pulling that is hard to stop. A body-focused repetitive behaviour.
Trigeminal nerve
The main nerve in your face.
Tryptophan
An amino acid the body uses to make serotonin and melatonin.
Tryptophan shunt
When the body diverts tryptophan away from making serotonin and into the stress response pathway instead, depleting mood and sleep hormones simultaneously.
TSH (thyroid-stimulating hormone)
A hormone that regulates thyroid function. Measured in hormonal panels.
TTH (tension-type headache)
The most common kind of headache, often felt as a tight band around the head.
Tyrosine
An amino acid the body uses to make dopamine and noradrenaline.

U

Ubiquinol
The active, reduced form of CoQ10. Better absorbed than ubiquinone, particularly in people over 40.
Ubiquinone
The oxidised form of CoQ10. The more common supplement form, which the body converts to ubiquinol.
UV (ultraviolet) light
Invisible light from the sun that affects skin and helps the body make vitamin D.

V

Vagus nerve
The body's superhighway between the brain and the gut.
Vagus nerve stimulation
Gently stimulating the vagus nerve with small electrical impulses to help calm the nervous system.
Vestibular
Relating to the inner ear system that controls balance and spatial orientation.
Vibroacoustic therapy
A therapy that combines low-frequency sound vibration with music, delivered through a mat, chair, or bed. Used for stress reduction, pain, and nervous system regulation.
Vitamin B1 (thiamine)
Essential for converting blood sugar into energy. Low B1 is linked to insulin resistance and type 2 diabetes.
Vitamin B12
Essential for nerve function, energy, and mood. Deficiency is common in people on plant-based diets.
Vitamin B2 (riboflavin)
Essential for energy production and migraine prevention.
Vitamin B6 (pyridoxine)
Essential for making dopamine, serotonin, GABA, and glutathione.
Vitamin B9 (folate)
Essential for making serotonin, dopamine, and noradrenaline. Deficiency is strongly linked to depression.
Vitamin D
The sunshine hormone, essential for mood, immune function, and dopamine production.

W

White noise
White noise contains every audible frequency at once, which masks other sounds.
Whole-body vibration
Standing or sitting on a platform that vibrates gently, used to relax muscles and calm the nervous system.
Working memory
Your ability to hold information in your mind for a short time while you use it, such as remembering a phone number while you dial it.