The 98-year-old was admitted to Asha Parekh hospital in suburban Santacruz on August 16.
"He is on life support system. One of his lungs is not functioning. He is also having respiratory problems," Dr Vinod Khanna, Orthopaedic surgeon at Asha Parekh hospital told PTI.
Hangal slipped and fell down in his bathroom on August 13, fracturing his right femur (thigh) bone.
The doctors could not operate on him because of his weak condition.
The yesteryear actor, who has acted in over 200 films, is best known for character roles in films like 'Namak Haram', 'Sholay', 'Shaukeen', 'Aaina', 'Bawarchi' and others.
Recently, he returned to face the studio lights after seven years for TV Series 'Madhubala'.