Recapitalization - Schedule of Common Stock to be issued of the Business Combination (Details) - Class A Common Stock [Member]	9 Months Ended
Sep. 30, 2025 shares
Schedule of Common Stock to be issued of the Business Combination [Member]
NVAC Public Shares, outstanding prior to the Business Combination	1,357
Less: Redemption of NVAC Class A Common Stock	(5)
Public shares of NVAC	1,352
NVAC Founder Shares, outstanding prior the Business Combination	53,780
NVAC Representative Shares converted to Class A Common shares	6,000
NVAC Shares from Rights converted to Class A common shares	25,300
Profusa Shares [Member]
Business Combination shares
Business combination shares	114,584
Issuance of Shares in Connection with PIPE [Member]
Business Combination shares
Business combination shares	38,691
Conversion of Notes into Shares [Member]
Business Combination shares
Business combination shares	197,099
Common Stock Immediately after the Business Combination [Member]
Business Combination shares
Business combination shares	436,806

No definition available.

Name:	ck0001859807_BusinessCombinationSharesAbstract
Namespace Prefix:	ck0001859807_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Redemption of nvac class a common stock.

+ References

No definition available.

+ Details

Name:	ck0001859807_LessRedemptionOfNVACClassACommonStock
Namespace Prefix:	ck0001859807_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

NVAC founder shares, outstanding prior the business combination.

+ References

No definition available.

+ Details

Name:	ck0001859807_NVACFounderSharesOutstandingPriorTheBusinessCombination
Namespace Prefix:	ck0001859807_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

NVAC public shares, outstanding prior to the business combination.

+ References

No definition available.

+ Details

Name:	ck0001859807_NVACPublicSharesOutstandingPriorToTheBusinessCombination
Namespace Prefix:	ck0001859807_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

NVAC representative shares converted to class A common shares.

+ References

No definition available.

+ Details

Name:	ck0001859807_NVACRepresentativeSharesConvertedToClassACommonShares
Namespace Prefix:	ck0001859807_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

NVAC shares from rights converted to class A common shares.

+ References

No definition available.

+ Details

Name:	ck0001859807_NVACSharesFromRightsConvertedToClassACommonShares
Namespace Prefix:	ck0001859807_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

Public shares of NVAC.

+ References

No definition available.

+ Details

Name:	ck0001859807_PublicSharesOfNVAC
Namespace Prefix:	ck0001859807_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

Number of shares of equity interest issued or issuable by acquirer as part of consideration transferred in business combination.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 805
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 8
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479328/805-10-50-8

Reference 2: http://www.xbrl.org/2003/role/exampleRef
-Topic 805
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 41
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479303/805-10-55-41

Reference 3: http://www.xbrl.org/2003/role/exampleRef
-Topic 805
-SubTopic 30
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479581/805-30-50-2

Reference 4: http://www.xbrl.org/2003/role/exampleRef
-Topic 805
-SubTopic 30
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (b)(4)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479581/805-30-50-1

Reference 5: http://www.xbrl.org/2003/role/exampleRef
-Topic 805
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 42
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479303/805-10-55-42

+ Details

Name:	us-gaap_BusinessAcquisitionEquityInterestsIssuedOrIssuableNumberOfSharesIssued
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 805
-SubTopic 30
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479581/805-30-50-2

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 805
-SubTopic 30
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (e)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479581/805-30-50-1

+ Details

Name:	us-gaap_BusinessCombinationSegmentAllocationLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	us-gaap_StatementClassOfStockAxis=us-gaap_CommonClassAMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_BusinessAcquisitionAxis=ck0001859807_ProfusaSharesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_BusinessAcquisitionAxis=ck0001859807_IssuanceOfSharesInConnectionWithPIPEMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_BusinessAcquisitionAxis=ck0001859807_ConversionOfNotesIntoSharesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_BusinessAcquisitionAxis=ck0001859807_CommonStockImmediatelyAfterTheBusinessCombinationMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: