Raju, who is in Chanchalguda Jail, was given first aid by the jail authorities after he complained of chest pain. He was then shifted to Nizam's Institute of Medical Sciences (NIMS).
Doctors said he was undergoing treatment in intensive care unit and his condition was stable. Raju is already suffering from Hepatitis B and is being treated for the same, sources said.
It was on Jan 7, 2009 that Raju shocked the corporate world by admitting Rs 7,800 crore accounting fraud in the IT major.
Ramalinga Raju and other accused have been charged with cheating and criminal conspiracy.