Pak news portal The Namal had earlier reported that Musharraf had been put on a ventilator as his health had deteriorated. There were also reports in a section of media that Musharraf had passed away but these were subsequently denied.
Amyloidosis is the name for a group of rare, serious conditions caused by a build-up of an abnormal protein called amyloid in organs and tissues throughout the body.
The build-up of amyloid proteins (deposits) can make it difficult for the organs and tissues to work properly. Without treatment, this can lead to organ failure, according to National Health Service, UK.
Musharraf, who was born in New Delhi, took power in a coup in 1999. He served as president of Pakistan from 2001 to 2008.
The former dictator had launched the Kargil operation without the civilian government's approval. Aides of former prime minister Nawaz Sharif have said that Musharraf had also sought to derail talks with India through Kargil Operation.
After the partition, Musharraf's family settled in Karachi where he attended Saint Patrick's School.
He joined the Pakistan Military Academy at Kakul and graduated from the institution in 1964. He was subsequently commissioned in the Pakistan army.