THE 94-year-old former South African president and anti-apartheid icon has struggled with respiratory problems in recent years. These are his recent hospital stays:
Jan 26, 2011: Hospitalised for respiratory problems. Discharged after two days.
Feb 25, 2012: Enters hospital for "long-standing abdominal pain". Discharged a day later after a keyhole abdominal examination showed there was nothing seriously wrong.
Dec 8, 2012-Jan 6, 2013: Initially admitted for medical tests, Mandela spends much of December in hospital for treatment of the lung infection and surgery to have gallstones removed.
The stay was his longest in hospital since his release from prison in 1990.
March 9: Admitted to hospital for a scheduled medical check-up. Discharged a day later and reported by the government to be "well"..
March 28-April 6: Spends about 10 days in hospital for treatment of pneumonia. Discharged after a "sustained and gradual improvement" in his condition, according to the government.
June 8: Taken to hospital with recurrence of a lung infection. In a "serious but stable" condition, the government said.
June 13: Hospital reports Nelson Mandela's health is slowly improving, although he still remains in a serious condition
June 13: The former President's health has further deteriorated and is described as 'critical'.