Speaking to media personnel, Hussain said the doctors overseeing his mother's treatment have asked her husband, Nawaz Sharif, to fly out to London to make further decisions since her health was an important matter.
Consequently, the former premier decided to file an appeal to the court to grant him a leave of absence.
Kulsoom Nawaz "remained in the hospital for 10 hours and had to be brought again the next day", Hussain added, noting that she was "given drips".
"She wished to return home, so we brought her back with us. The doctors, however, have requested her to stay under their care.
"I request the nation to pray for her health," he said.
While on a trip to London "for his regular medical check-up", Shehbaz Sharif, the Chief Minister of Punjab, also visited Kulsoom Nawaz in the hospital.
He reiterated Hussain's statement about the ex-prime minister's wife faring well and said he prays for her health.
"I came to London for my medical check-up, which is going on," he said.