KUALA LUMPUR, Feb 9 — Former prime minister Tun Dr Mahathir Mohamad has admitted there were times during his recent hospitalisation at the National Heart Institute (IJN) when he felt his prognosis was bleak.

In a short video shared on his official Twitter account, the 96-year-old expressed his gratitude to the medical staff at IJN for helping him to overcome the "terrible” illness that had afflicted him, and thanked those who prayed for his recovery.

"There were times when I thought I would not recover, but Alhamdulillah (thanks to God), with the treatment that I received at IJN, I turned a corner.

"I can eat, walk and sleep. I am almost well but cannot do any work at the moment. But I will recover,” he said, albeit in a frail voice.

In another Twitter post, Dr Mahathir can be seen strolling around Putrajaya Lake, in the company of his wife, Tun Dr Siti Hasmah Mohd Ali.

The Langkawi MP was discharged from IJN four days ago and he has been recuperating at home ever since.

Dr Mahathir was warded at the hospital since early January for treatment after undergoing an elective procedure on January 9.

The exact nature of his illness has never been disclosed to the public.

The Parti Pejuang Tanah Air chairman will still be required to undergo follow-up treatment, IJN noted in a statement.