"The Hindi playback singer was admitted last week for respiratory and renal problems," Narayana Hrudayalaya spokesperson Vasuki told PTI here.
This is the second time since May that Dey has been hospitalised with same problems.
However, Dey's condition has improved ever since he was hospitalised, Vasuki said, adding, he has been undergoing dialysis.
Born in Kolkata, the Dadasaheb Phalke awardee currently resides in Bangalore after spending more than 50 years in Mumbai.
Dey, who started his playback career with 1943 film 'Tamanna', has sung nearly 3,500 songs in Hindi, Bengali, Gujarati, Marathi, Malayalam, Kannada and Assamese films.