Bharatiya Janata Party leader Uma Bharti was on Saturday admitted to a hospital in New Delhi after she complained of chest pain.
Her blood pressure also increased substantially, Bharti's close aides told PTI.
Doctors suspect she could have cardiac problem. She been advised to be under observation in the hospital for 72 hours, sources said.
At the moment she is stable and medical examinations are being conducted on her, they said.
The former Madhya Pradesh chief minister was to begin campaigning for the BJP in Bihar tomorrow for the assembly elections. The party considers her the best bet against Rashtriya Janata Dal leader Lalu Prasad Yadav.