Zuma suffers from blood pressure, diabetes and a heart condition
A heart condition, diabetes, high blood pressure and exhaustion are to blame for President Jacob Zuma's recent poor health.
This is according to a number of government and ANC insiders interviewed this week as the state of the president's health became the subject of increasing public speculation.
But Luthuli House is playing down the health scare. ANC spokesman Zizi Kodwa said the party was confident that Zuma would complete his new five-year term as head of state.
"There's no indication to us that we should worry about the health of the president. The president is well but I think he needs a rest," said Kodwa.
Concerns about the state of Zuma's health last year led some members of his family in Nkandla, KwaZulu-Natal, to suggest that he may decide to step down two years into his second term in office.
Zuma made his first public appearance after a 10-day break from his normal duties when he delivered the state of the nation address in parliament on Tuesday.
He looked frail and appeared to have lost weight. His walking seemed stiffer than usual and, when going down the marble steps to the National Assembly doors, he needed assistance from speaker Baleka Mbete, who was walking beside him.
Social media on Tuesday evening - and on the subsequent days of the parliamentary debate on Zuma's speech - were dominated by talk of how sickly and tired the president looked.
ANC MPs and staffers, however, remarked that the 72-year-old looked "much better" than he had before going on leave.
A Luthuli House official who attended a national executive committee lekgotla on June 6 to 8 said: "[At the NEC meeting] there was no voice, it was gone. This thing of not resting caught up with him. That man puts a lot on pressure on himself. It is those late-night meetings."
The ANC ordered Zuma to take a break after he failed to deliver his opening remarks to the lekgotla, complaining of severe pain at the back of his neck.
An ANC MP, who spoke on condition of anonymity because she has no authority to speak on Zuma's health, said: "He started by greeting the meeting and then, before he could speak, pointed to the back of his neck and said he was having a pain.
"People then stood up at that point and said since the president says he is not well, he should be allowed to go home and rest.
"It was suggested that the deputy president should take over and deliver his report."
A week before the lekgotla, there were unconfirmed reports of Zuma consulting doctors amid concerns over his blood pressure being too high.
The Presidency denied this at the time. Although presidential spokesman Mac Maharaj insisted that Zuma was in good health and that it was only exhaustion from the punishing election campaign schedule that had forced Zuma to take a break, a number of current and former associates of the president said his health has been a concern for some time.
"He does have a heart problem. That is why he had to see a cardiologist at that Durban hospital earlier this year. I have been aware of his heart condition since some three years ago," said a one-time Zuma political associate.
The Sunday Times reported earlier this year that Zuma had an unscheduled medical check-up at Entabeni Hospital in Durban in January.
The former political associate confirmed that the president was diabetic, an assertion that has also been made by several party insiders.
The ANC MP said: "This is why the president is careful about what he eats and never skips lunch, because you can't take medication on an empty stomach."
Zuma' s fourth wife, Bongi Ngema-Zuma - a diabetes awareness activist - insisted her husband "was still fine", saying doctors screened him for the disease during his one-day stay in a Pretoria hospital two weeks ago.
"He does screen for it. Remember, he does regular [checks]. Like just now, when the papers said [he was admitted to hospital], it was for comprehensive tests and screening," said Ngema-Zuma.
But Kodwa said it "was never a secret to the ANC" that Zuma was diabetic and insisted that the president was in good health for his age.
"That is not a secret ... the president being diabetic. He's never treated that as a secret. He's always had that [for] many years.
"The question has always been how does he keep himself young and healthy in spite of that? He's always emphasised a healthy lifestyle and diet so the issue of diabetes is not new."
Maharaj said the public's questions about Zuma's ability to continue doing his work were understandable, but he did not "believe that the speculation is all based on any substantial facts".
He said government statements had been "very clear" that Zuma was exhausted as a result of "a heavy workload".
He refused to comment on Zuma's failure to deliver his speech at the ANC lekgotla or talk about what he suffers from.
"All the funny things that people say, I don't know ... I wasn't at the NEC ... [ANC secretary-general Gwede Mantashe] has been on the record that he [Zuma] is exhausted. I don't think they will play around misleading the public on the health of a sitting president. We just have to accept that ... when [Mantashe] says that and the deputy president repeats it ... you have to accept that," said Maharaj.
A senior official at Luthuli House said the 10-day break had been good for Zuma.
"The man needed to rest ... and we can already see the fruits of him resting. If you saw on the week of the NEC - he was a different JZ. Now we can see he's coming back," he said.
The official said the election period and the process of choosing premiers and the new cabinet had taken their toll on Zuma and other senior leaders.
"Our lekgotla is supposed to be in July, but we moved it to June and then there was the opening of parliament. The cabinet and premiers were also decided at the same time.
"There were instances where [Zuma] would sleep in meetings ... That was the problem we were experiencing towards the elections.
"Even Cyril [Ramaphosa, deputy president] was sleeping half the time ... These guys are tired," said the insider.
Ngema-Zuma said the president was careful about his health, exercising every morning more vigorously than she did. "For a person his age, he is very religious about his morning. When I complain that I don't have time, he says: 'It's because you exercise when there is time. Make time for exercises.'"