---
name: Symptom
slug: symptom
type: signal
status: running
version: 4.2.1
released: "estimated 3.8 billion BCE"
maintainer: the body, reluctantly
dependencies:
  - underlying-cause
  - nervous-system
  - threshold-of-tolerance
  - observer-bias
license: Proprietary (you did not choose this)
tags:
  - biology
  - medicine
  - communication
  - inconvenience
  - truth-telling
---

Symptom

What it actually is

A message from a system about itself, sent through the only channel it has, addressed to an audience that often ignores it.

How it works

Something goes wrong upstream. The body, lacking a proper logging interface, converts internal state changes into perceptible signals: pain, pressure, fever, fatigue, bleeding, swelling, confusion. These are not the problem. These are the notification that a problem exists.

The symptom is read by the patient first, usually misinterpreted, then passed to a clinician, usually compressed, then entered into a system, usually simplified, then matched against a pattern, sometimes correctly.

Information degrades at every handoff. This is by design, in the sense that nothing about this was designed.

Features

Visible symptoms: accessible to others. Useful for social coordination and diagnosis. Prone to performance and suppression.
Invisible symptoms: accessible only to the host. Highly accurate, chronically dismissed.
Referred symptoms: the signal arrives in the wrong location. The heart sends distress signals to the left arm. Classic misdirection.
Prodromal symptoms: early warnings before the main event. Usually noticed only in retrospect.
Emergent symptoms: appear when multiple conditions interact. Not predictable from any single input.

Known bugs

Symptoms can persist after the underlying cause resolves. See: phantom limb, post-viral fatigue, grief that outlasts its object.
Symptoms can be absent when the underlying cause is severe. Conditions that present asymptomatically are the library books no one checked out until it was too late.
Identical symptoms map to hundreds of different causes. The signal is shared. The meaning is not.
Symptoms are rated by the observer, not the host. This introduces systematic error.

Error codes

SYM_001  Signal received, cause not found
SYM_002  Signal dismissed, cause progressing
SYM_003  Signal amplified beyond proportional cause (see: [anxiety](/anxiety))
SYM_004  Signal suppressed by host for social or economic reasons
SYM_005  Signal misattributed, treatment applied to wrong system
SYM_404  No symptom present; condition operating silently

Edge cases

A symptom can be the treatment for something else. Fever is both signal and response.
Some symptoms are only recognizable in combination. Alone they compile fine. Together they indicate failure.
Placebo effect produces symptom relief without addressing cause, which raises uncomfortable questions about what a symptom actually is.
Cultural context changes which signals are legible as symptoms. Exhaustion is a symptom in one context and a virtue in another.

FAQ

Q: Should I look up my symptoms online? A: You will. The spec cannot stop you. Be advised that the results will include both "mild dehydration" and "rare cancer" and that you will focus on the latter.

Q: Is ignoring a symptom the same as resolving it? A: Operationally, for a while, yes. Then no.

Q: Who owns my symptoms? A: You experience them. Insurance adjudicates them. Medicine classifies them. The pharmaceutical supply chain monetizes them. Ownership is contested.

drafting spec…