JOHANNESBURG (AFP) - Ailing anti-apartheid icon Nelson Mandela was admitted to hospital for a third time in four months late on Wednesday, receiving treatment for a recurrent lung infection.
The 94-year-old, once a spry boxer who stayed fit during his 27 years in prison by doing calisthenics in his cell, has grown increasingly frail as a nonagenarian.
He has been plagued by persistent respiratory problems over the years.
While serving his prison term, Mr Mandela was diagnosed with early stage tuberculosis, a disease which killed his father.
He was diagnosed in 1988 after being admitted to hospital in Stellenbosch with a bad cough and weakness and having complained of dampness in his cell.
Two litres of fluid were drained from his chest and he spent six weeks recuperating in the hospital before being transferred to a private clinic near his mainland Cape Town prison where he was the facility's first black patient.
"When the report came back from hospital they indicated that fortunately we sent the specimen before there were holes in the lung," he said in 2004. "I underwent treatment and was completely cured after four months."
It is just weeks since he was last discharged from a hospital in the capital Pretoria after a "scheduled medical check-up," amid growing fears about his health.
And the former statesman was also admitted on Dec 8 last year when he underwent treatment for a recurrent lung infection and surgery to extract gallstones before he was allowed to leave on Dec 26 for home-based care.
Yet lung ailments are not the only problem to beset the famed Nobel Peace Prize winner.
Friend and prominent human rights lawyer George Bizos recently reported Mr Mandela was suffering from memory lapses.
In Feb 2012 when he spent the night in hospital after a minor exploratory procedure to investigate persistent abdominal pain.
Madiba, as he is affectionately called in South Africa, underwent a diagnostic laparoscopy, or keyhole surgery, in which doctors made small incisions in the abdominal area to probe it with a tiny camera.
Mr Mandela had surgery in 1985 for an enlarged prostate gland that had caused a urinary blockage.
In 2001, he received radiotherapy treatment for prostate cancer and told reporters the following year that he had been given a clean bill of health against the disease.
The tear glands of Mr Mandela's eyes were damaged by years of being forced to smash limestone rocks in the quarry on Robben Island, due to the alkalinity of the stone, leaving them dry and prone to irritation.
He had cataract surgery, aged 75 in 1994, a few months after being sworn into office as president.
Press photographers were asked not to use camera flash when taking pictures of Mr Mandela.