<?xml version="1.0"?>
<ownershipDocument>
    <schemaVersion>X0201</schemaVersion>

    <documentType>4</documentType><periodOfReport>2004-01-02</periodOfReport>
    <issuer>
        <issuerCik>0001156039</issuerCik>
        <issuerName>ANTHEM INC</issuerName>
        <issuerTradingSymbol>ATH</issuerTradingSymbol></issuer><reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001192088</rptOwnerCik>
            <rptOwnerName>SULLIVAN DENNIS J JR</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>120 MONUMENT CIRCLE</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>INDIANAPOLIS</rptOwnerCity>
            <rptOwnerState>IN</rptOwnerState>
            <rptOwnerZipCode>46204</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
            <reportingOwnerRelationship>
<isDirector>1</isDirector><isOfficer>0</isOfficer><isTenPercentOwner>0</isTenPercentOwner><isOther>0</isOther></reportingOwnerRelationship></reportingOwner><nonDerivativeTable><nonDerivativeTransaction><securityTitle><value>Common Stock</value></securityTitle><transactionDate><value>2004-01-02</value></transactionDate><transactionCoding><transactionFormType>4</transactionFormType><transactionCode>A</transactionCode><equitySwapInvolved>0</equitySwapInvolved><footnoteId id="F1"/></transactionCoding><transactionAmounts><transactionShares><value>33</value></transactionShares><transactionPricePerShare><value>76.28</value></transactionPricePerShare><transactionAcquiredDisposedCode><value>A</value></transactionAcquiredDisposedCode></transactionAmounts><postTransactionAmounts><sharesOwnedFollowingTransaction><value>1372</value></sharesOwnedFollowingTransaction></postTransactionAmounts><ownershipNature><directOrIndirectOwnership><value>D</value></directOrIndirectOwnership><natureOfOwnership><value/></natureOfOwnership></ownershipNature></nonDerivativeTransaction></nonDerivativeTable><derivativeTable><derivativeTransaction><securityTitle><value>Phantom Stock Units</value><footnoteId id="F2"/></securityTitle><conversionOrExercisePrice><value>0</value><footnoteId id="F3"/></conversionOrExercisePrice><transactionDate><value>2004-01-02</value></transactionDate><transactionCoding><transactionFormType>4</transactionFormType><transactionCode>A</transactionCode><equitySwapInvolved>0</equitySwapInvolved></transactionCoding><transactionAmounts><transactionShares><value>32</value></transactionShares><transactionPricePerShare><value>76.28</value></transactionPricePerShare><transactionAcquiredDisposedCode><value>A</value></transactionAcquiredDisposedCode></transactionAmounts><exerciseDate><footnoteId id="F4"/></exerciseDate><expirationDate><footnoteId id="F4"/></expirationDate><underlyingSecurity><underlyingSecurityTitle><value>Common Stock</value></underlyingSecurityTitle><underlyingSecurityShares><value>32</value></underlyingSecurityShares></underlyingSecurity><postTransactionAmounts><sharesOwnedFollowingTransaction><value>32</value></sharesOwnedFollowingTransaction></postTransactionAmounts><ownershipNature><directOrIndirectOwnership><value>D</value></directOrIndirectOwnership><natureOfOwnership><value/></natureOfOwnership></ownershipNature></derivativeTransaction></derivativeTable><footnotes><footnote id="F1">Exempt under Rule 16b-3(d)(1)</footnote><footnote id="F2">The phantom stock units were accrued under the Anthem, Inc. (&quot;Company&quot;) Board of Directors' Deferred Compensation Plan (&quot;The Plan&quot;).</footnote><footnote id="F3">The Conversion or Exercise Price of the Derivative Security is 1-for-1.</footnote><footnote id="F4">The phantom stock units shall be payable in Company common stock at the time designated in the reporting person's election made under the Plan in accordance with the terms of the Plan.</footnote></footnotes><remarks/><ownerSignature><signatureName>Nancy Purcell, Attorney-in-fact</signatureName><signatureDate>2004-01-06</signatureDate></ownerSignature></ownershipDocument>

