| Cover | Mar. 30, 2023 |
| Cover [Abstract] | |
| Entity Registrant Name | Ra Medical Systems, Inc. |
| Entity Central Index Key | 0001716621 |
| Document Type | 8-K |
| Amendment Flag | false |
| Entity Emerging Growth Company | true |
| Document Period End Date | Mar. 30, 2023 |
| Entity Ex Transition Period | false |
| Entity Incorporation State Country Code | DE |
| Entity File Number | 001-38677 |
| Entity Tax Identification Number | 38-3661826 |
| Entity Address Address Line 1 | 1670 Highway 160 West Suite 205 |
| Entity Address City Or Town | Fort Mill |
| Entity Address State Or Province | SC |
| Entity Address Postal Zip Code | 29708 |
| City Area Code | 973 |
| Local Phone Number | 691-2000 |
| Security 12b Title | Common Stock, par value $0.0001 per share |
| Trading Symbol | RMED |
| Security Exchange Name | NYSE |
| Written Communications | false |
| Soliciting Material | false |
| Pre Commencement Tender Offer | false |
| Pre Commencement Issuer Tender Offer | false |
