Every pillar on this site uses terms that don’t get defined on first use, because the post that introduced them assumed you’d look it up. This page is that lookup. Plain-language definitions for the recurring biomarkers, nervous-system terms, and site-coined concepts — nothing here is medical advice, just a shared reference.
Precision Longevity terms
ApoB (Apolipoprotein B) — A protein found on every artery-clogging lipoprotein particle in your blood. Because it counts particles rather than the cholesterol packed inside them, many cardiologists consider it a more direct measure of cardiovascular risk than standard LDL cholesterol.
hs-CRP (high-sensitivity C-reactive protein) — A blood marker of low-grade, chronic inflammation. Unlike the CRP test used to catch acute infections, the “high-sensitivity” version is sensitive enough to flag the quiet, long-running inflammation linked to cardiovascular and metabolic disease.
Sarcopenia — The age-related loss of muscle mass and strength. It’s gradual, often invisible on a scale, and the reason “muscle as a retirement plan” shows up repeatedly across Precision Longevity content — strength is what keeps independence intact later in life.
Grip strength — A simple, low-tech proxy for overall muscular and functional health, often used in research as a predictor of broader health outcomes because it correlates with total-body strength and physical resilience.
SHBG (sex hormone-binding globulin) — A protein that binds circulating testosterone and estrogen, making them biologically inactive while bound. SHBG rises with age, which is why “total testosterone” alone can be a misleading number without it.
Hypogonadism — The clinical term for low testosterone. Diagnosing it requires both a consistently low lab result and real symptoms — a low number alone, with no symptoms, isn’t a diagnosis.
STRAW+10 — The medical framework doctors use to stage perimenopause and menopause, based on menstrual cycle changes and hormone markers rather than symptoms alone.
Timing hypothesis — The finding that hormone replacement therapy’s cardiovascular risk depends heavily on when a woman starts it relative to menopause — lower risk starting within 10 years of menopause and under age 60, higher risk starting later.
Bioidentical hormones — Hormone formulations molecularly identical to what the body produces. The word describes chemical structure, not a different safety profile — compounded “bioidentical” products also skip the dosing consistency and safety monitoring FDA-regulated products go through.
MACE (major adverse cardiac events) — The standard trial endpoint for serious heart problems (heart attack, stroke, cardiovascular death) used to measure a treatment’s cardiovascular safety.
Endothelial dysfunction — When the thin lining of your blood vessels stops widening and relaxing as readily as it should. Researchers often treat it as an early sign of vascular strain, and measure it by how much an artery opens up after a brief pause in blood flow.
Periodontitis — Severe gum disease: ongoing infection and inflammation that damages gum tissue and the bone holding your teeth in place. It usually starts as milder gum inflammation (gingivitis), which is why bleeding gums are worth taking seriously.
Fat-free mass — Everything in your body that isn’t fat: muscle, bone, organs and water. Studies on weight loss often track it as a stand-in for muscle, though it’s an imperfect one.
VO2peak — The highest rate at which your body can take in and use oxygen during hard exercise. It’s a standard lab measure of aerobic fitness.
Mild cognitive impairment (MCI) — Memory or thinking problems that are noticeable and measurable beyond normal aging, but not severe enough to take away a person’s independence in daily life. Some people with MCI go on to develop dementia; others stay stable or improve.
Episodic memory — Memory for specific personal experiences — what happened, where, and when, like a conversation you had last week. It is often one of the first kinds of memory to slip in Alzheimer’s disease.
Surgical menopause — Menopause caused by surgically removing both ovaries (bilateral oophorectomy), which stops ovarian hormone production all at once. Natural, or spontaneous, menopause happens gradually as the ovaries wind down on their own.
White matter hyperintensities — Bright spots on certain brain MRI scans that mark damaged areas in the brain’s white matter, the wiring that connects brain regions. They are usually tied to disease of the brain’s small blood vessels, become more common with age and high blood pressure, and larger amounts are linked to higher stroke and dementia risk.
Glycosylation (hyperglycosylation) — The process cells use to attach sugar chains to proteins and fats, which shapes how those molecules fold and work. Hyperglycosylation means more of this sugar-tagging than normal.
Somatic Resilience terms
Vagal tone — A measure of how responsive your vagus nerve is — the nerve most responsible for shifting your body out of “fight or flight” and into rest-and-digest mode. Higher vagal tone is generally associated with faster recovery from stress.
HRV (heart rate variability) — The variation in time between consecutive heartbeats. Counterintuitively, more variability is the healthy sign — it reflects a nervous system that can flexibly shift between stress and recovery states rather than staying locked in one.
Orthosomnia — Anxiety about sleep caused by obsessively monitoring sleep-tracker data. The tracker becomes the source of the sleep problem it was meant to solve.
Cyclic sighing — A breathing pattern (a double inhale through the nose followed by a long exhale) studied as a fast way to shift the nervous system toward calm, distinct from generic “deep breathing.”
Downstate / Upstate — Site shorthand for your nervous system’s recovery mode (downstate) versus its activated, performance mode (upstate). The core Somatic Resilience thesis is that both states need to be deliberately engineered, not left to chance.
Interoception — Your sense of what’s going on inside your body: heartbeat, breathing, hunger, muscle tension. Body-awareness practices train it, and researchers are still working out how best to measure it.
Craniovertebral angle — A measurement of head posture: the angle between a horizontal line through the base of your neck and a line to your ear. A smaller angle means your head sits further forward.
Deep sleep (slow-wave sleep) — The deepest stage of non-REM sleep, also called N3, marked by slow, large brain waves. It is the hardest stage to wake someone from.
REM sleep (rapid eye movement sleep) — The sleep stage when most vivid dreaming happens. Brain activity looks close to waking, the eyes dart back and forth, and most of the body’s muscles are temporarily switched off.
Polysomnography — An overnight sleep study that records brain waves, eye movements, muscle activity, breathing, heart rhythm, and blood oxygen. It is the standard way to measure sleep stages and diagnose sleep disorders.
Cognitive Sovereignty terms
Digital Sovereignty — Site-coined term for setting the terms of your relationship with technology deliberately, rather than defaulting to whatever a notification, feed, or app is optimized to make you do.
Attention residue — The cognitive trace left behind when you switch tasks, even briefly. It measurably degrades performance on whatever you turn to next — the underlying reason “just glancing” at a notification isn’t free.
Cognitive Sovereignty — The pillar name for treating focus as a finite, defendable resource rather than something that should be available to any app or notification that asks for it.
Bipolar spectrum — The range of mood conditions that involve episodes of elevated mood. Bipolar I includes at least one full manic episode; bipolar II includes milder hypomanic episodes plus major depressive episodes; subthreshold forms have symptoms that don’t meet the full criteria for either.
Cross-pillar terms
Vitality Span — Site-coined alternative to “lifespan” or “healthspan” — the stretch of years you’re not just alive, but capable of doing the things that make life worth extending in the first place.
Tactical Health Infrastructure — The site’s framing for its own content: not a single hack or supplement, but the small set of durable systems (sleep, strength, blood work, attention) that compound over years.
Implementation intention — An if-then plan that ties a specific action to a specific cue, such as “If the coffee is brewing, then I’ll do ten slow breaths.” Research finds it works better than a vague resolution.
Automaticity — How little effort or conscious thought a behavior takes. Habit researchers use it as the measure of whether something has become a habit.
Hazard ratio — A comparison of how often an event, such as a diagnosis or death, happens over time in one group versus another. A ratio of 1.0 means no difference, 0.74 means a 26% lower rate, and 1.25 means a 25% higher rate. On its own it shows an association, not a cause.
Comorbidity — Having two or more health conditions at the same time, such as ADHD and bipolar disorder. Comorbid conditions can share symptoms, which can make each one harder to recognize and diagnose.
Missing a term? This page gets updated as new posts introduce new vocabulary — check back, or follow the link from wherever you found the term.
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