---
title: "Glossary data"
description: "The clinical-to-plain-English term list as a flat, searchable table. It is the machine twin of the Plain-English A to Z."
url: "https://opsinjs.pensievelabs.org/reference/generated/glossary"
source: "https://opsinjs.pensievelabs.org/reference/generated/glossary.md"
section: "Reference"
kind: "reference"
reviewed: "2026-09-02"
reviewer: "content"
aliases: ["term data", "glossary table", "plain english data"]
---
> Elements written as `` below are opsinjs documentation
> components. Their attributes are the content: the values they render are
> generated from `tokens/*.json` and `registry/catalogue.ts` and are
> published separately at https://opsinjs.pensievelabs.org/r/index.json and under the Reference
> section.
> Nothing is missing from this page. The data simply does not live in
> the prose.
## How this is generated [#how-this-is-generated]
**Source:** `tokens/glossary.json`, which is the same file the `` component
reads at runtime, so a term that renders in a product is a term that appears here.
**Script:** `scripts/build-reference.mts`. **Command:** `pnpm run generate`.
**This is not the page you want if you are reading.**
[Plain-English A to Z](../../content/plain-english-a-z.mdx) is canonical: it is
written to be read, it groups terms, it explains the judgement behind each
replacement, and it is where a change to the guidance is made. This page is its
flat twin, and the twin carries one row per term with every field of the source
exposed. It exists so that search, the `.md` twins and `/r` all cover the glossary
without anybody writing a second copy of it by hand.
**Five columns.** *Term* is the clinical or technical word. *Plain* is the
replacement to use in an interface. *Definition* is the one-sentence explanation
shown when a reader expands a ``. *Aliases* are the other spellings and
abbreviations a search should match. *Notes* carries the caveat, where the plain
word is not an exact synonym and the difference could matter. Those rows are the
ones worth reading twice.
**Provenance.** Every definition here is written for this project. Nothing is
copied from the NHS A to Z or any other Crown-copyright source; where a source
informed a definition it is cited on the canonical page, not pasted here. A
glossary is exactly the kind of asset that gets copied without checking, so the
rule is absolute.
{/* opsinjs:generated:begin - everything below is replaced by scripts/build-reference.mts */}
## A-Z [#a-z]
| Term | Say this instead | Show both | Why |
| ------------------ | ------------------------------------------------------------------------------------------ | ---------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| acute | sudden, or short-lasting | first-use | Often misread as 'severe'. It describes how quickly something started, not how bad it is. |
| adherence | taking a medicine the way it was prescribed | plain-only | 'Compliance' frames the reader as obedient or not; 'adherence' is better but still clinical. Write what actually happened instead. |
| adverse effect | an unwanted effect of a medicine | first-use | 'Adverse' is not everyday English. 'Side effect' is understood, but it can make a serious effect sound minor, so say what the effect is. |
| benign | not cancer | always | This word appears on reports and is one of the few whose plain meaning is genuinely reassuring, so the reader should be able to match the two. |
| biomarker | something measurable in your body that says something about your health | first-use | Common in product copy, almost never understood outside research. |
| blood pressure | the pressure of blood pushing against the walls of your arteries, written as two numbers | first-use | The words are familiar but the two-number format is not. Always explain which number is which where both are shown. |
| BMI | a number worked out from your height and weight | always | The abbreviation is widespread and the calculation is not. Anywhere BMI is shown, say that it does not distinguish muscle from fat and is a poor guide for some people. |
| bradycardia | a slower than usual heart rate | first-use | Appears in device output. Also note that a slow resting heart rate is expected in many fit people. |
| cholesterol | a fatty substance carried in your blood | first-use | Widely known as a word, widely misunderstood as a single number. Most reports give several. |
| chronic | long-lasting, or ongoing | first-use | Often heard as 'severe'. It describes duration. |
| contraindication | a reason this treatment is not safe for you | plain-only | A word with no everyday equivalent that readers guess at. Never show it. |
| diastolic | the pressure between heartbeats, which is the lower of the two blood pressure numbers | always | The reader's own record shows the clinical word, so both are needed to match them up. |
| eGFR | an estimate of how well your kidneys are filtering | always | Appears on results with no explanation. The word 'estimated' matters and should never be dropped. |
| false positive | a result that says something was found when it was not there | first-use | Essential for interpreting any screening result honestly, and impossible to explain after the fact if the first screen did not mention it. |
| fasting | not eating or drinking anything except water for a set time before a test | first-use | Readers frequently assume water is included. Say the time and say that water is allowed. |
| HbA1c | your average blood sugar over about the last three months | always | One of the most common results a consumer app displays and one of the least understood. Also flag that it is reported in two different units worldwide. |
| HDL | one of the types of cholesterol measured in a blood test | always | Frequently described to readers as 'good cholesterol'. Avoid that shorthand: it invites the reader to treat one number as a verdict. |
| hypertension | blood pressure that stays higher than the usual range | first-use | Frequently confused with 'tension' in the sense of stress. |
| hypoglycaemia | blood sugar that has dropped below the range you were given | always | Time-critical. The reader may already know it as 'a hypo', and both forms must be recognisable. |
| in range | inside the range this test uses for comparison | plain-only | The replacement for 'normal'. Always name whose range it is: a laboratory's range, a device maker's range, or a range a clinician set for this person. |
| LDL | one of the types of cholesterol measured in a blood test | always | Usually captioned 'bad cholesterol'. Same objection as HDL: it turns one number into a moral judgement. |
| malignant | cancer | always | Never soften this and never show it without a route to a person. See /docs/health/emergency-and-escalation. |
| mg/dL | milligrams per decilitre, which is a unit used for blood test results | always | See mmol/L. Converting between the two is a correctness surface, not a display preference. |
| mmol/L | millimoles per litre, which is a unit used for blood test results | always | The same measurement is reported in mmol/L in some countries and mg/dL in others, and the numbers are not close. Never show a value without its unit. |
| oedema | swelling caused by fluid building up | first-use | Spelled two ways depending on country; the plain wording avoids the problem entirely. |
| out of range | outside the range this test uses for comparison | plain-only | The replacement for 'abnormal'. It states a fact about a comparison and leaves the interpretation to whoever is entitled to make it. |
| prognosis | what is likely to happen next | plain-only | A word no component should ever need. If a product is showing a prognosis, a clinician wrote it. |
| reference range | the range a test result is compared against | always | The most important term in this glossary. A reference range is a comparison, not a target, and it belongs to a laboratory or a device rather than to the reader. Always name whose range it is and never call it a normal range. |
| remission | a period when the signs of an illness have reduced or gone | first-use | Often heard as 'cured'. The plain wording keeps the distinction. |
| resting heart rate | how many times your heart beats a minute when you are at rest | first-use | Understood as words but frequently confused with the heart rate shown during activity. Say when it was measured. |
| screening | a test offered to people with no symptoms, to look for a possible problem early | first-use | Readers commonly assume a screening test is diagnostic. It is not, and the difference determines what the result means. |
| SpO2 | an estimate of how much oxygen your blood is carrying | always | Shown by consumer devices as a bare percentage. The word 'estimate' is not optional: the measurement is affected by movement, cold hands and skin tone, and the product must say so. |
| systolic | the pressure while your heart beats, which is the higher of the two blood pressure numbers | always | See diastolic. |
| tachycardia | a faster than usual heart rate | first-use | Appears in device output with no explanation and reliably alarms people. |
| titration | changing a dose in small steps until it is right for you | plain-only | No everyday equivalent; the plain wording is complete on its own. |
| triglycerides | a type of fat measured in a blood test | always | Appears on the same report as cholesterol and is routinely mistaken for it. |
## Words we do not use [#words-we-do-not-use]
| Never | Instead | Why |
| ----------- | -------------------------------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| abnormal | outside the usual range | The counterpart of the same problem, and the version that frightens people. |
| bad | the specific finding, stated plainly | Carries a verdict the system is not entitled to give. |
| diagnosis | say what the reading is and who can interpret it | opsinjs components never diagnose. Using the word implies they do. |
| don't worry | state what the reading means and what happens next | Reassurance the system cannot back up, and it reads as a reason to worry. |
| elevated | higher than | Clinical register; means little to a lay reader, and it sounds like a verdict to the readers who do recognise it. |
| failed | outside the range we expected | A reading is not a test the reader sat. |
| good | say the direction - higher, or lower | Moral framing of something largely outside the reader's control. |
| healthy | in the usual range | A verdict on a life, from one number. A reading can sit inside a range while the person is unwell, and outside it while they are fine. |
| just | delete it | 'Just a bit high' minimises a reading the reader may need to act on. |
| negative | the test did not find \ | Same collision, in the other direction. |
| normal | in the usual range, or the expected range for you | Outside a reference range is not abnormal in the everyday sense of the word, and inside one is not a clean bill of health. 'Normal' also carries a judgement about the person rather than about the reading. This word is banned outright across the system, including in code identifiers. |
| optimal | in the usual range | Sets up every future reading as a decline, in the register of a fitness tracker rather than a clinic. |
| perfect | in the usual range | Sets up every future reading as a decline. |
| poor | lower than the range for you | Judges the person, not the measurement. |
| positive | the test found \ | In everyday English 'positive' means good news. In a test result it usually means the opposite, and the collision is dangerous. |
| unhealthy | higher than the usual range | The same verdict in the other direction. Say which way the reading sits and against whose range; the replacement wording assumes the common case, so where the reading is low, say 'lower than the usual range'. |
{/* opsinjs:generated:end */}