<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2019-08-06</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000860730</issuerCik>
        <issuerName>HCA Healthcare, Inc.</issuerName>
        <issuerTradingSymbol>HCA</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001433376</rptOwnerCik>
            <rptOwnerName>Elcan Patricia F</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>3100 WEST END AVENUE</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>NASHVILLE</rptOwnerCity>
            <rptOwnerState>TN</rptOwnerState>
            <rptOwnerZipCode>37203</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock, par value $0.01 per share</value>
            </securityTitle>
            <transactionDate>
                <value>2019-05-21</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>5</transactionFormType>
                <transactionCode>G</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value>E</value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>20840.6623</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0.00</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>797414.6264</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>Held indirectly through Hercules Holding II</value>
                    <footnoteId id="F1"/>
                    <footnoteId id="F2"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock, par value $0.01 per share</value>
            </securityTitle>
            <transactionDate>
                <value>2019-08-06</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>250</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>124.0952</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>997017.289</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>Held indirectly by Spouse and Children</value>
                    <footnoteId id="F1"/>
                    <footnoteId id="F3"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock, par value $0.01 per share</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>41052</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                    <footnoteId id="F2"/>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock, par value $0.01 per share</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>2277437.3653</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>Held indirectly through Hercules Holding II by Patricia Frist Elcan 2018 Annuity Trust III</value>
                    <footnoteId id="F1"/>
                    <footnoteId id="F4"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock, par value $0.01 per share</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>1490201.9224</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>Held indirectly through Hercules Holding II by Patricia Frist Elcan 2019 Annuity Trust I</value>
                    <footnoteId id="F1"/>
                    <footnoteId id="F4"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock, par value $0.01 per share</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>3547122.4752</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>Held indirectly by GRATs</value>
                    <footnoteId id="F1"/>
                    <footnoteId id="F5"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock, par value $0.01 per share</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>461046.2045</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>Held indirectly by Patricia F. Elcan Grat III Trust II</value>
                    <footnoteId id="F1"/>
                    <footnoteId id="F6"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock, par value $0.01 per share</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>237863.9997</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>Held indirectly by Patricia F. Elcan Grat II Trust I</value>
                    <footnoteId id="F1"/>
                    <footnoteId id="F7"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock, par value $0.01 per share</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>439142.8945</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>Held indirectly by Elcan Investment Partnership</value>
                    <footnoteId id="F1"/>
                    <footnoteId id="F8"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock, par value $0.01 per share</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>169207.7998</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>Held indirectly by Elcan Children's Trust</value>
                    <footnoteId id="F1"/>
                    <footnoteId id="F9"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock, par value $0.01 per share</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>36629163.8593</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>Held indirectly through Hercules Holding II by Frisco, Inc.</value>
                    <footnoteId id="F1"/>
                    <footnoteId id="F10"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">Hercules Holding II (&quot;Hercules&quot;) holds 68,912,077 shares of common stock of HCA Healthcare, Inc. Hercules is held by a private investor group, including affiliates of HCA Inc. founder Dr. Thomas F. Frist Jr. The Reporting Person may be deemed to be a member of a group exercising voting and investment control over the shares of common stock of HCA Healthcare, Inc. held by Hercules. However, the Reporting Person disclaims membership in any such group and disclaims beneficial ownership of these securities, except to the extent of her pecuniary interest therein.</footnote>
        <footnote id="F2">The Reporting Person jointly owns with her spouse 41,052 shares of common stock of HCA Healthcare, Inc. and 776,573.9641 units of Hercules and therefore may be deemed to own indirectly the same number of shares of common stock of HCA Healthcare, Inc. by virtue of her ownership in Hercules.  The Reporting Person owns 20,840.662342 units of Hercules and therefore may be deemed to own indirectly the same number of shares of common stock of HCA Healthcare, Inc. by virtue of her ownership in Hercules.</footnote>
        <footnote id="F3">The Reporting Person may be deemed to have indirect beneficial ownership in respect of 35,201 shares of common stock of HCA Healthcare, Inc. through an indirect pecuniary interest in such shares held by her spouse and children. In addition, the Reporting Person may be deemed to have indirect beneficial ownership in respect of 961,816.289 units of Hercules, through an indirect pecuniary interest in such units held by her spouse and children, and therefore may be deemed to own indirectly the same number of shares of common stock of HCA Healthcare, Inc.</footnote>
        <footnote id="F4">The Reporting Person may be deemed to be the beneficial owner of the units of Hercules held by The Patricia Frist Elcan 2018 Annuity Trust III and the Patricia Frist Elcan 2019 Annuity Trist I, each of which she serves as trustee, and therefore may be deemed to own indirectly the same number of shares of common stock of HCA Healthcare, Inc.</footnote>
        <footnote id="F5">The Reporting Person is trustee of three grantor retained annuity trusts for the benefit of her children, and the Reporting Person's spouse is trustee of nine grantor retained annuity trusts for the benefit of the Reporting Person's children. The Reporting Person may, accordingly, be deemed to be the beneficial owner of the aggregate 51,131 shares of common stock of HCA Healthcare, Inc. held by such trusts. In addition, the Reporting Person may be deemed to be the beneficial owner of the 3,495,991.4752 units of Hercules held by such trusts and therefore may be deemed to own indirectly the same number of shares of common stock of HCA Healthcare, Inc.</footnote>
        <footnote id="F6">The Reporting Person's spouse is the trustee of the Patricia F. Elcan Grat III Trust II, and the Reporting Person may therefore be deemed to be the beneficial owner of the 23,148 shares of common stock of HCA Healthcare, Inc. held by such trust. The Reporting Person may also be deemed to be the beneficial owner of the 437,898.2045 units of Hercules held by such trust and therefore may be deemed to own indirectly the same number of shares of common stock of HCA Healthcare, Inc.</footnote>
        <footnote id="F7">The Reporting Person's spouse is the trustee of the Patricia F. Elcan Grat II Trust I, and the Reporting Person may therefore be deemed to be the beneficial owner of the 11,943 shares of common stock of HCA Healthcare, Inc. held by such trust. The Reporting Person may also be deemed to be the beneficial owner of the 225,920.9997 units of Hercules held by such trust and therefore may be deemed to own indirectly the same number of shares of common stock of HCA Healthcare, Inc.</footnote>
        <footnote id="F8">The Reporting Person may be deemed to be the beneficial owner of the 22,049 shares of common stock of HCA Healthcare, Inc. held by Elcan Investment Partnership, of which Mrs. Elcan, her spouse and a trust of which Mrs. Elcan and her spouse serve as co-trustees are the general partners. The Reporting Person may also be deemed to be the beneficial owner of the 417,093.8945 units of Hercules held by Elcan Investment Partnership and therefore may be deemed to own indirectly the same number of shares of common stock of HCA Healthcare, Inc.</footnote>
        <footnote id="F9">The Reporting Person's spouse is the trustee of the Elcan Children's Trust, and the Reporting Person may therefore be deemed to be the beneficial owner of the 8,495 shares of common stock of HCA Healthcare, Inc. held by such trust. The Reporting Person may also be deemed to be the beneficial owner of the 160,712.7998 units of Hercules held by such trust and therefore may be deemed to own indirectly the same number of shares of common stock of HCA Healthcare, Inc.</footnote>
        <footnote id="F10">The Reporting Person may be deemed to share voting and dispositive power with respect to 36,629,163.8593 shares of HCA Healthcare, Inc. beneficially owned by Frisco, Inc., by virtue of her position as a director of Frisco, Inc. Frisco, Inc. has beneficial ownership of 36,629,163.8593 units of Hercules, and therefore may be deemed to own indirectly the same number of shares of common stock of HCA Healthcare, Inc.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ Natalie Harrison Cline, Attorney-in-Fact</signatureName>
        <signatureDate>2019-08-08</signatureDate>
    </ownerSignature>
</ownershipDocument>
