His daughter Koyel Ahmed and wife Runy Zaman informed the media that the actor was suffering from Asthma and breathing difficulties, along with other health complications for the last couple of days.
According to the doctors, his oxygen level decreased and his condition would have deteriorated if there was any delay in hospitalisation.
His overall condition improved on Thursday as his oxygen saturation level increased to 98 percent from 83 percent. Results of his tests are satisfactory, according to his family.
Abu Taher Mohammad (ATM) Shamsuzzaman was born on September 10, 1941, at Daulatpur of Noakhali. His career began as an assistant director in Udayan Chowdhury's film 'Bishkonnya' (1961).
His acting career began in 1965 but he earned his big break as an antagonist in Amjad Hossain's film 'Nayanmoni' (1976).
In his career, ATM Shamsuzzaman wrote more than a hundred screenplays. He debuted as a director with the film 'Ebadat' in 2009.
The legendary comedian and antagonist won six National Film Awards for best actor in Kazi Hayat's 'Dayee Ke?' (1987), best actor (comedy) in 'Madam Fuli' (1999), 'Churiwala' (2001), 'Mon Boshe Na Porar Table E' (2009), best supporting actor in 'Chorabali' (2012) and the lifetime achievement award in 2017.
He was awarded the Ekushey Padak in 2015 for his outstanding contribution to the Bangladeshi cinema industry.