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
U.S. president serve more than two terms. Roosevelt died shortly after beginning his fourth term in 1945, and two years later Congress passed a bill to amend the Constitution to establish a two-term limit on the presidency.