Pakistan Peoples Party (PPP) co-chairperson and former president after his health deteriorated.
A medical team, led by Dr Asim Hussain, is examining the former president, said sources, adding that a “procedure” will be performed on Zardari’s lungs.
The medical team will conduct further tests of the former president after the “procedure” is completed, they say.
This is the second time that Zardari has been admitted to a hospital this year.
A similar situation developed in February this year when former president Asif Ali Zardari had been admitted to a private hospital in Karachi after his health deteriorated.