Americans want a president with the steadiest possible finger on the nuclear button, which is why they worry about the state of health of their presidential candidates, and why nowadays candidates often try to quash doubts about their health by releasing their medical records. Sometimes they overdo it, as in the case of Senator John McCain, who published 1,173 pages of medical records when he was the Republican presidential nominee in the 2008 election. There was too much there for anyone to absorb, but Barack Obama, who won that election, made do with just a brief letter from his Chicago doctor saying he was ‘in excellent health’.

Doctors of potential presidents tend to give them good reports, and they even gave a good reference to Dick Cheney when he was running to be the vice-president of George W. Bush in 2000. They also found him to be in ‘excellent health’, but went on to mitigate this cheering assessment with disconcerting detail. Mr Cheney, they said, had taken medication for heart disease, gout and metabolic disorders; had suffered three heart attacks and undergone quadruple coronary bypass surgery; had been treated for skin cancer; and, most alarmingly, had a ‘potentially fatal allergic reaction, known as anaphylaxis, from pomegranates’. This last piece of information might have been very useful to a terrorist, but the doctors thought he was nevertheless well suited for the vice-presidential job.

Coming to the present day, Donald Trump has avoided giving any detail about his condition but has attracted much mockery by releasing an overblown encomium by his doctor, Harold Bornstein. Dr Bornstein described his lab tests as ‘astonishingly excellent’ and an examination of his body as having shown ‘only positive results’. ‘Mr Trump, I can state unequivocally, will be the healthiest individual ever elected to the presidency,’ he concluded. Questioned by media reporters, Dr Bornstein explained that he had written his letter in a great hurry in five minutes, with a car waiting, and in language inspired by Trumpian rhetoric. ‘I think I probably picked up his kind of language,’ he said.

Hillary Clinton had already been described in a letter by her doctor as ‘in excellent physical condition and fit to serve as President of the United States’, but this hadn’t stopped Mr Trump from raising suspicions about her health. ‘To defeat crime and radical Islamic terrorism in our country, to win trade in our country, you need tremendous physical and mental strength and stamina,’ he said in one speech. ‘Hillary Clinton doesn’t have that strength and stamina.’ Mrs Clinton retorted that it was nonsense (‘I don’t go around questioning Donald Trump’s health. As far as I can tell, he’s as healthy as a horse’), but it might be ‘part of the wacky strategy, just say all these crazy things and maybe you can get some people to believe you.’ And maybe such a strategy would have some success, for a long history of presidential cover-ups has bred wide scepticism.

There was the case of President Grover Cleveland, who had oral cancer and in 1893 had a tumour removed from his mouth on a yacht while claiming to have gone on a fishing trip. Then Woodrow Wilson had several secret strokes that were eventually so incapacitating that his wife, Edith, is claimed to have said: ‘I don’t know why you men make such a fuss; I had no trouble running the country while Woody was sick.’ The public knew that Franklin Delano Roosevelt was wheelchair-bound because of polio when running for the presidency for the fourth time, but they did not know that he also had advanced heart disease that may have helped kill him a few months after his election; and they were also unaware that John F. Kennedy, whom they had seen as healthy and vibrant during his campaign, had suffered from Addison’s disease and severe back pain that could have affected his judgment when he reached the White House.

The other potential problem is mental illness. A study conducted in 2006 by psychiatrists at Duke University, North Carolina, found that 18 of America’s first 37 presidents met today’s criteria for psychiatric disorder. It also concluded that Teddy Roosevelt and Lyndon Johnson would have been diagnosed with bipolar disorder. So it may be wise to question the value of these medical records. Donald Trump may be ‘the healthiest individual ever elected to the presidency’, but does that cover his mental condition as well?