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
Others were convinced that Roosevelt's third term would signal America's acquiescence to a dictatorship. Still others were disturbed by Roosevelt's apparent dismissal of tradition  no president had ever run for a third term.