Churchill: Heart attack in 1941 concealed 

National leaders are usually middle-aged or older and at risk of disabling diseases. They may deny their illnesses and persuade their staff and doctors to lie to the public. There is a considerable literature on this topic, including the former Foreign Secretary David Owen's In Sickness and in Power: Illness in Heads of Government During the Last 100 Years (Methuen, 2008). Lord Owen, himself a doctor, listed 26 leaders including Hitler, Yeltsin and Blair whose health problems were concealed from the public.

In the 20th century, Britain had 19 Prime Ministers, nine of whom had their terms of office curtailed by illness. 

Three PMs from 1940 to 1957 — Winston Churchill, Clement Attlee and Anthony Eden — were looked after either at St Mary's Hospital, London, or by my predecessors there as senior physicians-gastroenterologists such as Sir Charles Wilson (later Lord Moran) and Dr Thomas Hunt. Each of the three premiers had historically important illnesses before they assumed office. 

Winston Churchill had chronic minor and non-disabling indigestion at least from 1912 when he had stomach pains that woke him with the acid regurgitation of heartburn. He was treated conventionally with ulcer-type
diets and carbonates of sodium, magnesium and bismuth. In 1950, he recalled that he had been "tortured" by his indigestion, but had been cured by massage. 

In 1922, he saw Lord Dawson. In 1936, he saw Hunt. Educated at St Paul's, Magdalen, St Mary's and Vienna, Hunt was an orator and a linguist. He had stature, authority, courtesy, enthusiasm and curiosity and was the diplomat of British and world gastroenterology. He joined the staff of St Mary's in 1930 and his advice was sought by many writers, whose vivid accounts of their illnesses are excellent. Churchill wrote: "The indigestion comes on during the night but disappears after the exercises in the morning. Painting always tries me highly...It is the mental concentration which seems to affect the stomach. I always paint standing up, as otherwise the indigestion would be very severe." Churchill told Hunt: "The thing that gave most indigestion was the effort of trying to get just the right colour for a sunset on a canvas and not the strain of political and national affairs." 

X-rays of his stomach, duodenum and gall bladder revealed that everything was normal. Hunt concluded that the indigestion was of the nervous hyperacidity type, telling Churchill that his nervous tension caused painful contractions of the stomach. Hunt taught, "All creative artists are a group especially subject to dyspepsias of doubt and anxiety...My experience of generals and admirals makes me believe that their training for action relieves them of most doubts, except from that concerning their future promotion."