---
title: "Reference range for a biomarker"
method: POST
path: "/api/agent/lookup_reference_range"
tags: ["reference"]
---

# Reference range for a biomarker

`POST /api/agent/lookup_reference_range`

## Request

- Base URL: `https://www.test-well.com`
- URL: `https://www.test-well.com/api/agent/lookup_reference_range`
- Auth: none declared

Physician-reviewed reference range for a blood test marker (130+ markers), filtered by sex and age when they matter, with what high and low values suggest, retest cadence, how to get tested, cited sources and the review date. Educational; the user's own report range takes precedence.

## Request body

- object
  - `marker` string, required: Marker name or alias, e.g. 'TSH', 'ferritin', 'HbA1c', 'LDL'
  - `sex` 'male' | 'female'
  - `age` integer
  - `pregnancy` boolean
  - `postmenopausal` boolean

## Response `200`

Tool result

- object
  - `tool` 'lookup_reference_range', required
  - `result` object, required
    - `found` boolean
    - `marker` string
    - `aliases` string[]
    - `category` string
    - `units` string[]
    - `measures` string
    - `filteredToQuery` boolean
    - `ranges` object[]
      - `qualifier` string: Who the band applies to, e.g. 'Female, age 18+'
      - `range` string
      - `min` number
      - `max` number
      - `unit` string
    - `highSuggests` string, nullable
    - `lowSuggests` string, nullable
    - `retest` string, nullable
    - `howToTest` object[]
      - `name` string
      - `kind` string
      - `price` number: USD
      - `url` string: Absolute https URL on test-well.com
    - `citations` object[]
      - `label` string
      - `url` string
    - `suggestions` string[]
    - `browse` string

## Other responses

- `400`: Invalid input
- `429`: Rate limited

---

[API](https://skmtc.dev/test-well/apis/testwell-agent-api.md) · [All operations](https://skmtc.dev/test-well/apis/testwell-agent-api/llms.txt) · [OpenAPI document](https://skmtc.dev/test-well/apis/testwell-agent-api/revisions/6e260731dfa4?raw)