"Manisha Koirala was admitted to our hospital on November 28," Jaslok Hospital spokesperson Krishnakant Dasyam said.
"She is undergoing some medical tests and will be in the hospital for some time," Dasyam, who is also Head Marketing at Jaslok Hospital & Research Centre, said.
The actress, who was in Nepal earlier this month, flew to Mumbai for further tests when she fell unconscious. She had also tweeted about suffering from a bout of food poisoning a few days ago.
Her father and brother are set to fly down to the city to be by her side while her mother Sushma is keeping her company.
Manisha, who hails from a prominent family in Nepal, has worked in several Hindi, Tamil and Malayalam movies.
The 42-year-old actress debuted with Subhash Ghai's movie Saudagar in 1991 and recently made a comeback with Ram Gopal Varma's Bhoot Returns.
Photograph: Pradeep Bandekar
(with inputs from PTI)