"She is fine and the medicines are having effect on her. Her health condition is progressing well but she is still on oxygen and the infection remains," Pradip Tandon, the chief executive officer (CEO) of the Belle Vue Clinic, told.
"It seems the treatment will be time-consuming," he said.
Suchitra Sen was admitted to Belle Vue Clinic Monday night with chest infection, which caused breathlessness.
A three-member team of doctors, including physician Subrata Moitra, is taking care of her.
Daughter Moonmoon Sen visited her late Wednesday night and said Bollywood starlets Raima and Riya Sen, granddaughters of Suchitra, would also come to see her soon.
Good wishes for speedy recovery came from Bollywood giants of yesteryears.
Dilip Kumar and Dev Anand, two giants of Hindi cinema with whom Suchitra paired in films like Devdas and Bombai Ka Babu respectively, wished her speedy recovery.
"I have happy experiences of working with her in Devdas, one of my favourite films," Dilip Kumar said.
In October last year, Sen was admitted to the same nursing home with high fever.
Suchitra, who dominated the Bengali film industry in the 1950s and 60s, left the industry in 1978 after a career of over 25 years, and since then has been living in seclusion.