Freedom Fighter Kakon Bibi Bir Protik was admitted to the intensive care unit (ICU) of MAG Osmani Medical College Hospital due to serious health complications on Monday night.
Dr Mosaddek Hossain, a doctor of the hospital, said she was suffering from asthma and heart diseases for long and recently she got an attack of pneumonia.
The freedom fighter was admitted under the observation of medicine expert Dr Nazmul Islam, said Dr Mosaddek.
"Later, she was shifted to the intensive care unit under the observation of Dr Sabyasachi Roy," he said.
A medical board will be formed on Wednesday for her treatment, he added.
In 1971, Kakon Bibi was arrested and brutally tortured by Pakistani army as she worked as a war spy and fought against the Pak army.
According to UNB, she fearlessly took part around 20 direct wars actively.
She sustained bullet wounds on her leg at the Ambari fight. Bibi still bears the bullet marks on her body.
At present, Kakon Bibi along with her family is living at Jirargaon of Doarabazar upazila in Sunamganj district.