BNP chairperson Khaleda Zia has been undergoing treatment at the Evercare Hospital in the capital.
Her condition is now stable, said Khaleda Zia's personal physician and BNP vice chairman AZM Zahid Hossain.
As part of regular check-ups, different examinations are still being carried out.
Speaking to Prothom Alo over phone on Thursday, Zahid Hossain said Khaleda Zia's treatment is being carried out under the supervision of the medical board.
Khaleda Zia, who tested positive for Covid-19, was admitted to the hospital on Tuesday.
Meanwhile, a 10-member medical board has been formed to treat Khaleda Zia.