Dr. Andrew Thillainayagam said Gibb had recently caught pneumonia because he was weakened from chemotherapy and two operations.
The 62-year-old singer fell into a coma last week after contracting the pneumonia. Thillainayagam said that three days ago he had warned Gibb's family that he may not wake up. Instead, Gibb is now fully conscious and able to speak.
Thillainayagam said Gibb is still in intensive care and is "exhausted, extremely weak and malnourished." He is breathing with the help of an oxygen mask and needs intravenous feeding and antibiotics.
"It is testament to Robin's extraordinary courage, iron will and deep reserves of physical strength that he has overcome quite incredible odds to get where he is now," Thillainayagam said in a statement.
He added: "Robin's wife, Dwina and son, Robin-John, his son Spencer and daughter Melissa have been at his bedside every day, talking to him and playing his favorite music to him. They have been tireless in their determination never to give up on him."
Gibb has been ill for several months and he cancelled multiple public appearances last year. He has said on his website last year that he had been seriously ill but did not give more details. He did tell the BBC he had a growth on his colon that was removed. Several media outlets have reported he has cancer.
The Bee Gees - British-born, Australia-raised brothers Robin, Barry and Maurice Gibb - had a string of disco-era hits including "How Deep is Your Love" and "Stayin' Alive."
Associated Press
