| Cover | Nov. 10, 2021 |
| Cover [Abstract] | |
| Document Type | 8-K |
| Amendment Flag | false |
| Document Period End Date | Nov. 10, 2021 |
| Entity File Number | 001-37467 |
| Entity Registrant Name | Astria Therapeutics, Inc. |
| Entity Central Index Key | 0001454789 |
| Entity Tax Identification Number | 26-3687168 |
| Entity Incorporation, State or Country Code | DE |
| Entity Address, Address Line One | 100 High Street |
| Entity Address, Address Line Two | Floor 28 |
| Entity Address, City or Town | Boston |
| Entity Address, State or Province | MA |
| Entity Address, Postal Zip Code | 02210 |
| City Area Code | 617 |
| Local Phone Number | 349-1971 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Title of 12(b) Security | Common Stock, $0.001 par value per share |
| Trading Symbol | ATXS |
| Security Exchange Name | NASDAQ |
| Entity Emerging Growth Company | false |
| Entity Information, Former Legal or Registered Name | Catabasis Pharmaceuticals, Inc. |
