Other causes of nausea include side effects from medications, pain, pregnancy and morning sickness, seasickness, viral infection, alcohol toxicity, and disease of the brain, esophagus, stomach, gallbladder, liver, pancreas, and intestine.
so roosevelt was able to win more than two terms because there was not yet a formal term limit on the presidency and the unique conditions when he ran for his third and fourth terms made his arguments for breaking with tradition acceptable to a majority of american voters
That was why Franklin Delano Roosevelt could run again in 1940 and 1944, becoming the only president to serve more than two terms. And that was why, three years later, in 1947, after sporadic public debate, Republicans demanded presidential term limits and changed the Constitution.