<?xml version="1.0" encoding="UTF-8"?>

<!--XBRL Document Created with the Workiva Platform-->
<!--Copyright 2025 Workiva-->
<!--r:13b084dd-9e50-4512-9a96-af0b9b23f94f,g:54378a50-3915-4b54-bf80-392c104a8525-->
<link:linkbase xmlns:link="http://www.xbrl.org/2003/linkbase" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.xbrl.org/2003/linkbase http://www.xbrl.org/2003/xbrl-linkbase-2003-12-31.xsd">
  <link:roleRef roleURI="http://www.exagen.com/role/Cover" xlink:type="simple" xlink:href="exdx-20250112.xsd#Cover"/>
  <link:presentationLink xlink:role="http://www.exagen.com/role/Cover" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_dei_CoverAbstract_f9eb9e2d-88fa-4974-bb68-f31ba4031784" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_CoverAbstract"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentType_5240cbe6-b0d0-4632-bfa0-eb8c9835cb5e" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_DocumentType"/>
    <link:presentationArc order="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_dei_CoverAbstract_f9eb9e2d-88fa-4974-bb68-f31ba4031784" xlink:to="loc_dei_DocumentType_5240cbe6-b0d0-4632-bfa0-eb8c9835cb5e" xlink:type="arc" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentPeriodEndDate_19868455-954f-489b-ae0e-8831ad89c52e" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_DocumentPeriodEndDate"/>
    <link:presentationArc order="2" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_dei_CoverAbstract_f9eb9e2d-88fa-4974-bb68-f31ba4031784" xlink:to="loc_dei_DocumentPeriodEndDate_19868455-954f-489b-ae0e-8831ad89c52e" xlink:type="arc" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityRegistrantName_b6e77f31-cfde-446e-bcb5-0cb52b892599" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_EntityRegistrantName"/>
    <link:presentationArc order="3" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_dei_CoverAbstract_f9eb9e2d-88fa-4974-bb68-f31ba4031784" xlink:to="loc_dei_EntityRegistrantName_b6e77f31-cfde-446e-bcb5-0cb52b892599" xlink:type="arc" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityIncorporationStateCountryCode_a263adb5-ce91-4b6d-83d0-48282ceeddea" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_EntityIncorporationStateCountryCode"/>
    <link:presentationArc order="4" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_dei_CoverAbstract_f9eb9e2d-88fa-4974-bb68-f31ba4031784" xlink:to="loc_dei_EntityIncorporationStateCountryCode_a263adb5-ce91-4b6d-83d0-48282ceeddea" xlink:type="arc" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityFileNumber_e6a5505a-66b7-44bf-99ca-361dc3cd7b11" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_EntityFileNumber"/>
    <link:presentationArc order="5" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_dei_CoverAbstract_f9eb9e2d-88fa-4974-bb68-f31ba4031784" xlink:to="loc_dei_EntityFileNumber_e6a5505a-66b7-44bf-99ca-361dc3cd7b11" xlink:type="arc" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityTaxIdentificationNumber_8347a453-a671-4a7a-9ff4-bbb1435f2cea" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_EntityTaxIdentificationNumber"/>
    <link:presentationArc order="6" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_dei_CoverAbstract_f9eb9e2d-88fa-4974-bb68-f31ba4031784" xlink:to="loc_dei_EntityTaxIdentificationNumber_8347a453-a671-4a7a-9ff4-bbb1435f2cea" xlink:type="arc" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityAddressAddressLine1_d9e737df-589b-473e-8637-c894a0037454" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_EntityAddressAddressLine1"/>
    <link:presentationArc order="7" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_dei_CoverAbstract_f9eb9e2d-88fa-4974-bb68-f31ba4031784" xlink:to="loc_dei_EntityAddressAddressLine1_d9e737df-589b-473e-8637-c894a0037454" xlink:type="arc" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityAddressCityOrTown_3cba6806-bdf3-4656-970f-5f3893e73482" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_EntityAddressCityOrTown"/>
    <link:presentationArc order="8" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_dei_CoverAbstract_f9eb9e2d-88fa-4974-bb68-f31ba4031784" xlink:to="loc_dei_EntityAddressCityOrTown_3cba6806-bdf3-4656-970f-5f3893e73482" xlink:type="arc" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityAddressStateOrProvince_d1675fe3-9f24-414c-90a7-f526fd1b7aa1" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_EntityAddressStateOrProvince"/>
    <link:presentationArc order="9" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_dei_CoverAbstract_f9eb9e2d-88fa-4974-bb68-f31ba4031784" xlink:to="loc_dei_EntityAddressStateOrProvince_d1675fe3-9f24-414c-90a7-f526fd1b7aa1" xlink:type="arc" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityAddressPostalZipCode_fb29f16c-d746-40f0-8be3-564135df9393" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_EntityAddressPostalZipCode"/>
    <link:presentationArc order="10" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_dei_CoverAbstract_f9eb9e2d-88fa-4974-bb68-f31ba4031784" xlink:to="loc_dei_EntityAddressPostalZipCode_fb29f16c-d746-40f0-8be3-564135df9393" xlink:type="arc" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_CityAreaCode_169d6c3c-1e89-4fc7-aba2-d5b20156eda7" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_CityAreaCode"/>
    <link:presentationArc order="11" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_dei_CoverAbstract_f9eb9e2d-88fa-4974-bb68-f31ba4031784" xlink:to="loc_dei_CityAreaCode_169d6c3c-1e89-4fc7-aba2-d5b20156eda7" xlink:type="arc" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_LocalPhoneNumber_42f92409-10dd-4c30-89bc-45f94117afbb" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_LocalPhoneNumber"/>
    <link:presentationArc order="12" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_dei_CoverAbstract_f9eb9e2d-88fa-4974-bb68-f31ba4031784" xlink:to="loc_dei_LocalPhoneNumber_42f92409-10dd-4c30-89bc-45f94117afbb" xlink:type="arc" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_WrittenCommunications_15163e16-00d6-4c96-bc62-4c6d65eed44c" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_WrittenCommunications"/>
    <link:presentationArc order="13" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_dei_CoverAbstract_f9eb9e2d-88fa-4974-bb68-f31ba4031784" xlink:to="loc_dei_WrittenCommunications_15163e16-00d6-4c96-bc62-4c6d65eed44c" xlink:type="arc" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_SolicitingMaterial_01e3c919-8639-4329-8c91-53123e2fcd6e" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_SolicitingMaterial"/>
    <link:presentationArc order="14" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_dei_CoverAbstract_f9eb9e2d-88fa-4974-bb68-f31ba4031784" xlink:to="loc_dei_SolicitingMaterial_01e3c919-8639-4329-8c91-53123e2fcd6e" xlink:type="arc" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_PreCommencementTenderOffer_81f57f25-d754-44a0-b579-202c9021d38e" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_PreCommencementTenderOffer"/>
    <link:presentationArc order="15" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_dei_CoverAbstract_f9eb9e2d-88fa-4974-bb68-f31ba4031784" xlink:to="loc_dei_PreCommencementTenderOffer_81f57f25-d754-44a0-b579-202c9021d38e" xlink:type="arc" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_PreCommencementIssuerTenderOffer_de30b439-8eb6-4fac-9133-5b4b52dcedc5" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_PreCommencementIssuerTenderOffer"/>
    <link:presentationArc order="16" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_dei_CoverAbstract_f9eb9e2d-88fa-4974-bb68-f31ba4031784" xlink:to="loc_dei_PreCommencementIssuerTenderOffer_de30b439-8eb6-4fac-9133-5b4b52dcedc5" xlink:type="arc" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_Security12bTitle_949d7cfa-7977-445a-a360-26e29650d595" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_Security12bTitle"/>
    <link:presentationArc order="17" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_dei_CoverAbstract_f9eb9e2d-88fa-4974-bb68-f31ba4031784" xlink:to="loc_dei_Security12bTitle_949d7cfa-7977-445a-a360-26e29650d595" xlink:type="arc" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_TradingSymbol_c7cb4773-9b82-48e7-ac4e-c6307bb83b1c" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_TradingSymbol"/>
    <link:presentationArc order="18" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_dei_CoverAbstract_f9eb9e2d-88fa-4974-bb68-f31ba4031784" xlink:to="loc_dei_TradingSymbol_c7cb4773-9b82-48e7-ac4e-c6307bb83b1c" xlink:type="arc" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_SecurityExchangeName_62992f8c-0286-4821-a91e-6c4a5fca501b" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_SecurityExchangeName"/>
    <link:presentationArc order="19" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_dei_CoverAbstract_f9eb9e2d-88fa-4974-bb68-f31ba4031784" xlink:to="loc_dei_SecurityExchangeName_62992f8c-0286-4821-a91e-6c4a5fca501b" xlink:type="arc" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityEmergingGrowthCompany_62146eb0-748e-445d-ab35-09a5c4069922" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_EntityEmergingGrowthCompany"/>
    <link:presentationArc order="20" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_dei_CoverAbstract_f9eb9e2d-88fa-4974-bb68-f31ba4031784" xlink:to="loc_dei_EntityEmergingGrowthCompany_62146eb0-748e-445d-ab35-09a5c4069922" xlink:type="arc" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityCentralIndexKey_2a07c0e2-b137-4698-9307-54c92f53a2db" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_EntityCentralIndexKey"/>
    <link:presentationArc order="21" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_dei_CoverAbstract_f9eb9e2d-88fa-4974-bb68-f31ba4031784" xlink:to="loc_dei_EntityCentralIndexKey_2a07c0e2-b137-4698-9307-54c92f53a2db" xlink:type="arc" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_AmendmentFlag_0d682ccb-7597-4362-92a5-c8e2661ee104" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_AmendmentFlag"/>
    <link:presentationArc order="22" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_dei_CoverAbstract_f9eb9e2d-88fa-4974-bb68-f31ba4031784" xlink:to="loc_dei_AmendmentFlag_0d682ccb-7597-4362-92a5-c8e2661ee104" xlink:type="arc" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
  </link:presentationLink>
</link:linkbase>
