WASHINGTON (AFP) - Donald Trump's shock announcement that he has coronavirus and his subsequent hospitalisation has sent the United States reeling.
However, the 45th president is hardly the first to suffer from a major illness or even a global pandemic while in office.
From George Washington to George W. Bush, here's a roundup of the US presidency's more memorable brushes with disease and death.
INVOKING THE 25TH
The US Constitution's 25th Amendment allows presidents to temporarily hand power to the vice-president while incapacitated, a process in which one organ - the colon - has played a starring role.
Mr George W. Bush invoked the 25th Amendment in 2002 and again in 2007 while being sedated for routine colonoscopies, putting then Vice-President Dick Cheney in charge for hours.
Although the amendment was adopted in 1967, Mr Ronald Reagan indicated in 1985 he did not believe he officially invoked it when he left then Vice-President George H. W. Bush briefly at the helm while doctors removed a cancerous polyp from his colon.
Mr Reagan said the period was too "brief and temporary" for the amendment to apply.
SECRET YACHT SURGERY
Hoping to avoid public attention, Grover Cleveland covertly stowed away for surgery at sea on a friend's yacht in 1893.
With the nation on the brink of an economic depression, Cleveland aimed to keep the cancer on the roof of his mouth a secret so as not to send the nation into a financial panic. He mostly succeeded.
The tumor, five teeth and a piece of his left jawbone were reportedly removed somewhere off the coast of New York, and a rubber prosthetic was later inserted for aesthetics.
Mr Trump is hardly the first US president to be laid low by a global pandemic, or play down the dangers only to become infected by the disease. Woodrow Wilson caught the Spanish flu in April 1919 while in France for the Paris peace talks negotiating the end to World War I.
Despite the grave nature of his health, his administration worked furiously to keep his illness from the general public.
GEORGE WASHINGTON FALLS ILL
In 1790, George Washington caught such a bad flu that it put the fate of the young nation in peril - should the president die, so might the country.
The street outside the presidential mansion, then in the temporary capital of New York, was closed off and covered in hay to muffle the noise while the first president, just a year into his administration, quietly convalesced.
"Beset by hiccups, Washington made strange gurgling noises that were interpreted as a death rattle," biographer Ron Chernow writes in his book Washington, A Life. The president survived.
Petersen House, the abode where Abraham Lincoln died in downtown Washington, is today part of the US National Park Service, a "dark tourism" destination where visitors can see where the 16th president spent his final hours after being shot in the head across the street at Ford's Theatre.
Lincoln died in the home's back bedroom the morning after the attack.
He is one of four US presidents murdered in office, all by gunfire.
James A. Garfield died of infection two months after being gunned down in 1881 by a disgruntled public office seeker.
Anarchist Leon Czolgosz killed president William McKinley in 1901. And John F. Kennedy was famously shot while riding in an open-top convertible in Dallas in 1963.
In addition, Reagan was seriously wounded in a 1981 assassination attempt outside a Washington hotel by a deranged gunman.
In 1850, president Zachary Taylor attended a July 4 dedication for the Washington Monument. After reportedly chugging iced milk and eating a large quantity of cherries, he fell ill and died several days later.
Contemporaries blamed the milk. Historians say the matter is still up in the air.
Three other presidents have also died of natural causes while in office: William Henry Harrison, Warren G. Harding and Franklin D. Roosevelt.
HEART ATTACKS AND STROKES
From a non-lethal heart attack and stroke suffered by Dwight D. Eisenhower to Roosevelt's fatal cerebral hemorrhage, a number of sitting presidents have suffered very common but potentially deadly ailments.
Following his bout with the Spanish flu, Wilson had a near fatal stroke in October 1919, after which his wife, Edith, secretly served as de facto decision-maker for his administration's remaining 17 months.