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
The only President who served more than two terms was Franklin D. Roosevelt, who was elected to four terms and served from 1933 until his death in 1945. The 22nd Amendment to the US Constitution was enacted in response to this.