---
title: "Health glyphs"
description: "The medical symbols opsinjs will not use, because an app that borrows the visual language of clinical authority is claiming something it has not earned."
url: "https://opsinjs.pensievelabs.org/foundations/iconography/health-glyphs"
source: "https://opsinjs.pensievelabs.org/foundations/iconography/health-glyphs.md"
section: "Foundations"
kind: "foundation"
reviewed: "2026-09-20"
reviewer: "engineering"
aliases: ["medical icons", "caduceus", "stethoscope", "cross symbol"]
---
> 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.
## Overview [#overview]
There is a standard visual vocabulary for "medical": a cross, a stethoscope, a
caduceus, a figure in a white coat, a pill, a syringe, an ECG trace. It is
instantly legible, it is what every stock icon set offers under the search term
"health", and opsinjs does not use any of it.
The reason is the same one that runs through the whole system. opsinjs presents
health data to a layperson; it does not practise medicine, does not diagnose,
does not triage, and confers no clinical status on the product that uses it. See
[Safety, scope and limitations](../../start/safety-scope-and-limitations.mdx). A
symbol that says "clinician" is a claim of authority, and putting one next to a
number changes how that number is read. A reading annotated with a stethoscope
reads as a clinical finding; the same reading annotated with a heart outline
reads as a measurement, which is what it is.
This is a design position, argued rather than measured. What is not a matter of
opinion is the specific legal point about the red cross emblem below, and the
fact that implying clinical status you do not hold is a regulatory question in
most jurisdictions. Check both with your own counsel rather than with a design
system.
## How it works [#how-it-works]
**The excluded set**, with the reason for each, because a ban without a reason is
just a preference:
| Symbol | Why not | Use instead |
| --------------------------------------------- | ------------------------------------------------------------------------------------------------------------------------ | --------------------------------------------------------------------------------------- |
| Red cross on white | Protected under the Geneva Conventions and their national implementing law; using it is a legal matter, not a design one | Nothing, because the concept it is reaching for is usually "urgent", which is a status |
| Any cross used to mean "medical" | Claims clinical authority; also carries specific religious and national meanings in different places | The glyph for the thing actually being measured |
| Caduceus or rod of Asclepius | Pure authority signalling, and widely confused with each other | Words |
| Stethoscope, white coat, clinician figure | Says "a doctor is involved"; usually one is not | The category glyph, or a person's own name |
| Syringe, needle, blood drop | Distressing to a large number of people, including many with the conditions the product is for | The name of the test, in words |
| Pill or capsule to mean "health" | Health is not medication; and to somebody managing a long-term condition the association is loaded | The specific concept: a dose, a reminder, a course |
| ECG trace as decoration | Implies a diagnostic reading where there is none; a decorative waveform is fabricated data | A real chart, or nothing |
| Tick, cross, thumbs-up, smiley beside a value | A verdict, delivered by a picture, with no source | [Clinical status](../../health/clinical-status-semantics.mdx), in colour, icon and word |
**What the system uses instead.** Category glyphs are drawn from the ordinary
world: the object being measured, or the activity being recorded. A bed for
sleep, a footprint for movement, a heart outline for heart rate. They are
descriptive rather than authoritative, they are legible without medical
knowledge, and they do not imply that anyone has interpreted anything.
**The status glyphs are abstract**, not medical: shapes that carry ordinal weight
without borrowing meaning from anywhere. They are always accompanied by a colour
and a word, so the glyph never has to be self-explanatory. That is what allows
them to be abstract in the first place.
**Emergency is a special case, and it is not a glyph problem.** Where a product
does need to tell somebody to seek immediate help, that is a screen with words,
a phone number and a stated source, decided by the product's clinical
governance. See
[Emergency and escalation](../../health/emergency-and-escalation.mdx). A red cross
is not an escalation mechanism; it is a picture where a sentence should be.
## Using it [#using-it]
**Ask what the glyph is claiming.** Every icon makes an implicit claim about who
is speaking. A stethoscope claims a clinician. A caduceus claims a profession. A
bed claims nothing at all, which is correct, because the product is reporting that
somebody was asleep.
A blood-glucose result headed with a plain droplet-free category glyph and the
metric's name in words, with the reading, its unit and who measured it.
The same result headed with a stethoscope and a red cross. Nothing has been
added to the reading. Without a word being written, a reader has been told
that a clinician has looked at it.
**Do not use a warning triangle as a status glyph by default.** It is the
strongest general-purpose alarm symbol most readers know, so spending it on the
second of four levels leaves nothing above it. What each level's glyph is belongs
to [clinical status semantics](../../health/clinical-status-semantics.mdx).
**Do not draw anatomy as decoration.** An organ illustration used as a section
header is a clinical image doing an ornamental job, and it will be read as
diagnostic by somebody. Locating a symptom is one job that genuinely calls for a
body diagram. Where that need is genuine, the diagram is a deliberate, specified
surface with its own rules: [Body diagrams](../imagery/body-diagrams.mdx).
**Do not borrow a national health service's marks, colours or symbols.** They
signal endorsement, they are usually protected, and the endorsement is not real.
The related content rule is on
[Official resources](../../project/official-resources.mdx).
## Tokens [#tokens]
This page constrains the icon mapping rather than owning tokens. The excluded set
is a rule on [Icon inventory](./icon-inventory.mdx), which is where a role resolves
to a glyph, and it is the natural place to enforce mechanically.
## Accessibility impact [#accessibility-impact]
* **A symbol that implies authority is a comprehension problem, not just a
regulatory one.** Readers with low health literacy are the most likely to take
a clinical-looking mark as evidence that a clinician has been involved, and
they are the readers the whole system is written for.
* **Needles, blood and clinical imagery cause real distress.** Needle phobia is
common, and people managing long-term conditions have accumulated associations a
design system cannot see. An icon that makes somebody close the app has
prevented them from reading their own data.
* **Abstract status glyphs are more accessible than medical ones**, because they
are learned in one place and always accompanied by a word, rather than depending
on prior knowledge the reader may not have.
* **Cultural legibility varies enormously and silently.** Crosses, colours and
gestures do not mean the same thing everywhere, and a reader who misreads a
glyph has no way to ask.
* **None of this removes the need for a text alternative.** Every meaningful
glyph still carries a name; choosing a better symbol is not a substitute for
labelling it.
## Related [#related]
* [Icon inventory](./icon-inventory.mdx) is the mapping these rules constrain.
* [Safety, scope and limitations](../../start/safety-scope-and-limitations.mdx)
says what opsinjs is and is not, which is the argument underneath this page.
* [Imagery → Illustration style](../imagery/illustration-style.mdx) covers the
same question one level up, for pictures rather than glyphs.