Archbishop Emeritus Nicholas Chia has woken up and spoken his first word since falling into a coma after a fall last month.

The former archbishop was "fairly conscious" on Thursday and was able to say "Hello" to his doctors, wrote Archbishop William Goh's personal assistant Magdalene Lee, in an internal statement.

"The large clot in his brain has since resolved, and the swelling in his head is subsiding," said Ms Lee. "The right side of his body remains weak, however, and will require physiotherapy."

Since Thursday, however, the 75-year-old has not uttered any further words, Ms Lee told The Straits Times, and is to remain in critical care at Mount Alvernia Hospital.

The Catholic Church will put out another statement when there is further "significant change in his condition".