nbc's erin mcloughlin has the story. >> reporter: with the president in the hospital, the nation's onk it's scary for our country. i think this is like a very unprecedented moment where we really don't know what's going on. >> reporter: while shocking, this is far from the first presidential health crisis. [ sound of gunfire ] >> after ronald reagan was shot in 1981, the white house released this photo, cropping out a nurse with a machine and a chest tube. >> history tells you to treat medical reports from the white house has, at best, incomplete and sometimes outright there are elements that can be manufactured to produce a certain political effect. >> reporter: in fact, many presidents suffered from prolonged illness in secret, including 101 years ago during the last pandemic. in the midst of the 1918 flu, woodrow wilson became ill. his condition later compounded by a stroke. his wife edith and advisers made presidential decisions for him until the end of his term. for years, fdr concealed his polio and his wheelchair among other health issues. during his re-election campaign, cropp