At the age of 43 years, John F. Kennedy was the youngest man ever elected president. Throughout both his campaign and his presidency, he was portrayed as the epitome of youth and vigor. In fact, he had the most complex medical history of anyone to occupy the White House. The recent opening of his White House medical records has provided researchers greater insight into the multiple medical conditions that afflicted Kennedy. A recent review of these records, coupled with other available sources, allows new understanding of his health history that can now be explained in the context of a unifying autoimmune endocrine disorder.