Prasad Yadav was today admitted to a hospital here for medical evaluation.
"This is a scheduled medical evaluation. There is no cause to panic," a spokesperson for the Asian Heart Institute, located in suburban Bandra Kurla complex, told PTI.
Asked if the 66-year-old leader would undergo a heart surgery, the spokesperson said, "That would be decided only after medical evaluation."
Votes for the by-elections to 10 Assembly seats in Bihar fought by him in partnership with long-time rival Nitish Kumar, are being counted today.