Parhaodd y straen sylweddol ar y GIG ym mis Rhagfyr 2021 yn sgil pwysau heriol y gaeaf, y don Omicron, a’r angen i gefnogi’r rhaglen frechu.
Demanding winter pressures, the Omicron wave and the need to support the vaccination programme continued to place considerable strain on the NHS in December 2021.