Former prime minister Nawaz Sharif will be initially treated for his cardiac disease and kidney ailment at the Sharif Medical City in Lahore, his physician said on Wednesday.

PML-N supreme leader Sharif was released from Kot Lakhpat jail late Tuesday night hours after the Supreme Court suspended his sentence in the Al-Azizia reference and granted him bail on medical grounds for six weeks.

But the reprieve came with the rider that he will not leave Pakistan during this period and will file a fresh petition before the Islamabad High Court (IHC) for further bail if his health condition deteriorates and he still needs medical attention.

Speaking to reporters today, Sharif's personal physician Dr Adnan Khan said the former premier is suffering from "significant heart disease" and his kidney functions have deteriorated recently, which is "a matter of concern".

"I had a lengthy conversation with him ... and upon my request, he will come to the hospital tomorrow morning," he said. Sharif is the chairman of the Board of Trustees of Sharif Medical City, which is run by his family trust.

According to the doctor, a team of experts is being compiled who will look after him and conduct an assessment as to what investigations and blood tests are required.

Responding to a question, Dr Khan said it will be determined after the initial evaluation if Sharif's treatment "will be possible to be completed within six weeks".