Three months prior to his third birthday, in 1920, Kennedy came down with scarlet fever, a highly contagious and life-threatening disease, and was admitted to Boston City Hospital.[392][13]
Years after Kennedy's death, it was revealed that in September 1947, while Kennedy was 30 and in his first term in Congress, he was diagnosed by Sir Daniel Davis at The London Clinic with Addison's disease, a rare endocrine disorder. Davis estimated that Kennedy would not live for another year, while Kennedy himself hoped he could live for an additional ten.[393] In 1966, White House physician Dr. Janet Travell revealed that Kennedy also had hypothyroidism. The presence of two endocrine diseases raises the possibility that Kennedy had autoimmune polyendocrine syndrome type 2 (APS 2).[394]
Kennedy also suffered from chronic and severe back pain, for which he had surgery. Kennedy's condition may have had diplomatic repercussions, as he appears to have been taking a combination of drugs to treat severe back pain during the 1961 Vienna Summit with Soviet Premier Nikita Khrushchev. The combination included hormones, animal organ cells, steroids, vitamins, enzymes, and amphetamines, and possible potential side effects included hyperactivity, hypertension, impaired judgment, nervousness, and mood swings.