Most people are prone to occasional exhaustion. Pneumonia is also a common affliction. But if you are running for the most powerful job in the world, a task demanding the stamina of a marathon runner, voters have a right to see your full health records. Hillary Clinton’s two-page medical summary contains more detail than the paragraph released by Donald Trump’s doctor. But it barely skims the surface of reasonable disclosure.

Having been caught on video collapsing with exhaustion in New York on Sunday, Mrs Clinton’s fitness is suddenly at the centre of the presidential campaign. Several hours later it turned out she had been diagnosed with pneumonia on Friday. Mrs Clinton may well be generally fit, as her doctor and she maintain. But she must purge an unhealthy instinct for privacy. The less voters know, the likelier they are to believe conspiracy theories put about by her enemies.

Unfortunately Mrs Clinton’s tendency to withhold information is deeply ingrained. This latest health scare is a good example of how badly that can backfire. While she was still secretary of state in 2012, Mrs Clinton fell and suffered a concussion that took her out of a full work schedule for weeks. It later emerged she took six months to fully recover from an episode that included a minor brain clot. She also suffered a previously undisclosed thrombotic clot in her leg in 2009 and a similar episode in 1998 when she was First Lady. In each instance, her desire for privacy was understandable. Yet at a point in the campaign when the marathon is turning into the final sprint, any secrecy is reckless. It risks lending credence to the poisonous and dishonest rumours from Mrs Clinton’s enemies, which run the gamut from Alzheimer’s to cancer. The price would have been far lower had she disclosed her pneumonia on Friday and cancelled weekend events. Now her every sneeze will be minutely analysed for signs of something worse.