Cover - USD ($) $ in Billions	12 Months Ended
	Dec. 31, 2021	Feb. 23, 2022	Jun. 30, 2021
Cover [Abstract]
Document Type	10-K
Document Annual Report	true
Document Period End Date	Dec. 31, 2021
Current Fiscal Year End Date	--12-31
Document Transition Report	false
Entity File Number	001-39562
Entity Registrant Name	PULMONX CORPORATION
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	77-0424412
Entity Address, Address Line One	700 Chesapeake Drive
Entity Address, City or Town	Redwood City
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	94063
Country Region	1
City Area Code	650
Local Phone Number	364-0400
Title of 12(b) Security	Common Stock, $0.001 par value per share
Trading Symbol	LUNG
Security Exchange Name	NASDAQ
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	false
ICFR Auditor Attestation Flag	true
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		37,018,943
Entity Public Float			$ 1.2
Documents Incorporated by Reference	Portions of the registrant’s definitive proxy statement relating to its 2022 annual meeting of stockholders (the “2022 Proxy Statement”) are incorporated by reference into Part III of this Annual Report on Form 10-K where indicated. The 2022 Proxy Statement will be filed with the U.S. Securities and Exchange Commission within 120 days after the end of the fiscal year to which this Annual Report on Form 10-K relates.
Entity Central Index Key	0001127537
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	FY
Amendment Flag	false